Sunday, 27 May 2012

Leading Techniques

1 - Squaring panels
2 - Wide edge cames
3 - Mitred Corners
4 - Tucking Cames
5 - Growing Panels
6 - Weaving
7 - Bending wide cames
8 - Leading small circles
9 - Leading Nuggets
10 - Leading tight curves
11 - False Lines in Leading
12 - Silhouettes in leaded glass
13 - Sculpting the came
14 - Copper foil in leaded panels

1 - Squaring panels

When building leaded glass panels to be placed in existing wooden frames, you need to make sure the panel is as square as the opening in the frame. The first requirement is to make sure your cartoon is squared, or has right angles at each corner.

I use a “roofing iron” as it is called in the UK. It is a steel tool about 600mm on one side and 400mm on the other. Its original use was to work out the pitch of roofs and check the same pitch was maintained all along the building. The first important thing – now that all roof trusses seem to be prefabricated – is that they still are in production. The second thing is that they all have a fixed right angle.

Roofing Square

Using this roofing iron will ensure your corners on the cartoon are right angles. This helps in the drawing of the cartoon as you only need set the iron on the base line and draw the verticals without having to measure the width higher up the cartoon. Of course you should check that the width is still correct at the top, just in case there has been a slip.

Then you have to stick to the cartoon.

When you are setting the battens to ensure the sides are held where you want them while you continue with the leading, the roofing iron again will ensure that you have placed the battens at right angles. You choose which line is to be your base, and nail or screw the batten into place. Ensure it is exactly parallel to your cut line and then align one side of the iron against it. Place the other batten snugly along the length of the other leg of the iron and you know you have a right angle.

When you are completed leading, but before soldering you can check on the accuracy of the angles by using the roofing iron again at each corner to check on the “squareness” of the whole panel. If the panel is out of square, you can tap on the battens not yet nailed/screwed in place to ease it all back into “square”

2 - Wide edge cames

The purposes of large perimeter cames are several.

Easy adjustment on site. It is often the case that windows are not totally regular in their dimensions, even though you have taken the measurements carefully. Variations in width and height can be accommodated by shaving the lead in appropriate places. This avoids having to take the panel back to the studio to reduce the size of the glass and put new perimeter came on the panel.

The width of the rebate has an effect on the width of the came to be used. The wider the rebate, the wider came you will want to use. The minimum width of came you want to use with a 10mm wide rebate is 10mm came. This will give a maximum of 2.5 mm of came showing if you have a glazing allowance of 5mm. Often 12 mm came is better. In general the came should be wider than the rebate is, but not so wide that the heart of the lead is outside the rebate. In church windows, where the panels are installed into the stone, the cames are frequently 16mm or 25mm wide to accommodate the variations in width and the flexibility needed to get the panels into the slots.

Aesthetics have an effect on the width of the perimeter came too. Various people want more or less came showing. The important limitation is that the heart of the lead should be within the rebate.

In autonomous panels the need for large edge cames is to act as a framing device. Zinc might be used but there are other possibilities than using a different metal that will provide as good or better solutions.

One option for framing, especially on edges of rectangular panels is to use lead. The lead touching the glass or copper foiled edge should be 10mm flat came. This allows you to insert a 5mm mild steel rod which is then covered by a 13mm flat came. The came leaves are smoothed by gentle pressure on the upper and lower flanges with a stopping or lead knife to bring the two flanges together. This gives a pleasant finish to the edge.

3 - Mitred Corners 

Completed Mitred Corner

There are various ways to determine where and at what angle to cut the lead came, especially for panels with more than four corners. The most common is a four cornered panel. The following method works for that circumstance very well.

My preference is to use the battens surrounding the cartoon as a guide for the placing of the mitres on the first two cames. The battens are placed around the cartoon to suit the came width. The vertical came is placed in contact with the bottom came. 

Setting the perimeter batten

A short piece of came – ca. 50 mm – is placed on the external cartoon line almost in contact with the vertical lead. A second short piece is placed on top of the short piece and extended over the top of the side lead.

Mark the lead lightly with a nail or pencil. Cut the angle from the inside to the outside corner. This will form a 45 degree angle.

Lower came marked for cutting from corner to line opposite

You can do the same for the bottom came, by removing the vertical came for the time being and doing the same operation on the horizontal came. Then they can be place back together for the next operation.

To determine the length of the came which is already mitred on one end, put the came in place on the cartoon. 

Then place a short piece of lead on the cut line which is at right angles to the came to be measured. Then place a short piece over the two cames as for the first mitre cut.

A nail or other pointed implement is used to scratch a line on each side of the overlapping lead. When this overlapping lead is removed, a diagonal is drawn from the inside mark to the outside mark. Cut along this diagonal.

There are other methods for panels with more than four right angles.

4 - Tucking Cames

It is most usual in many countries to butt lead cames against one another. In continental Europe the tucking of cames is more common. In this process, which has the advantages of speed and accuracy, the came is first fitted to the glass and then cut at the edge of the glass.

The first step is to cut the came to the appropriate angle to meet the lead to which it is to be joined. However before presenting the cut came to the joint, one end is lightly tapped with a small hammer to slightly curve the end of the came. This allows it to slip inside the leaves of the came to which it will be soldered. [overlap-leading]

The came is then shaped to the glass as normal. However, rather than removing the came for the next cut, the came is cut to the length of the glass, often using the glass as a guide. This end is then supported on the lead knife and tapped with the hammer to curve the end, ready for tucking into the next piece of came. Care is required so that you don’t crush the came and break the glass, nor miss the came and hit the glass or your fingers. With practice, there are few accidents.

Diagrammatically, the tucked lead looks like this

Leads tucked into the perimeter came

Tucking lead provides very accurate joints with no gaps for solder to fall through. Some argue it provides a stronger panel as the hearts of the jointed cames almost meet. The main immediate gain is quicker soldering.

5 - Growing Panels

What can be done to keep leaded glass panels from growing beyond their original cartoon lines?

I find that most people, who are not used to lead came, cut the crossing pieces too long so the whole panel grows. Each piece of came that is a fraction too long pushes the passing came out, making the glass apparently too large. Of course, this is an occasion to use the tucking method to reduce this cause of enlarging the panel. You can and should make sure that you have pressed the came snugly against the glass.

If the next piece of glass you place goes over the line allocated to it, something is wrong with the previous piece. Undo the came and check the size of the glass against the cartoon. If the glass fits inside the lines allocated, the problem is the way you have fitted the came to it. 

Pressing along the heart of the lead with an All Nova tool

Another check you can do is to run a felt tip pen at the side of the came onto the glass. Take the glass out and examine the space between the line and the edge of the glass. This will tell you where the glass and came are not fitting equally. A narrow space does not immediately mean the glass is too large, it may mean the came is not tucked against the glass properly. So check that first, before any grozing or grinding.

Oversized piece marked against the came

Glass piece removed from the came to observe the area that needs trimming (where the nail points)

Nails, push pins or other things that you can push into the work board will keep things stable. If you are working with a rectangle you can use wood battens. If not, multiple close spacing of nails will help. Also you could cut a piece of glass into a shape that will hold the outside of the panel.

6 - Weaving

"Weaving" is only easily and fully done where there is a grid. The example below shows a restoration project where the main part of the panel is a grid.
[photo weaving 1-3]]

This image shows the starting of the weaving. A short lead covering only one quarry has been placed horizontally - although you can start with a short vertical, both are fine. The next lead is vertical and covers two of the quarries. As you can see here the two quarries at the right are ready for the longer horizontal to be placed.

You proceed in this fashion - alternating long and short leads throughout the grid area.

As you can see this builds up in a diagonal fashion with each vertical and horizontal line being interrupted after every second piece of glass.

If you look closely you can also see that these leads are being tucked. This is easier with leads of 7mm and greater than of 6mm and less.

This method of leading gets its name from the similarity to representations of weaving in illustrations where a broken line represents the thread or reed going under another. Its purpose is to avoid hinges and so strengthen the whole panel. This avoidance of hinges makes the turning of the panel during soldering and cementing much easier.

Of course, you must remember that the glass is still the strongest part of the panel.

7 - Bending wide cames

The way to bend larger leads such as flat outside leads around pieces of tracery or other curved shapes in window panels is to lay the lead upon the bench, and use a curved, preferably wooden, lathekin or oyster knife.

Progressively manipulate the lead into the curve. Hold the lead steady by keeping your fingers spread on the top and back of lead and manipulate the curve between your extended fingers. Gently push the curved lathekin along the heart of the lead with small, smooth, circular strokes. Smooth the lead flanges by pressing down on the flanges on the inside of the curve as you go. If you try to do it too quickly the lead will probably buckle.

Frequently turn the lead over, applying the process to both sides.

If the flange crimps or buckles, put smooth jawed pliers inside the lead and squash the flange flat. The pliers can be used to flatten any kinks that develop in the lead.

The key is to handle the lead gently and in stages, gently flattening the complete lead and not flattening completely one spot before moving on to the next.

The advantage of round over flat in this circumstance is that round came of the same size can be bent into smaller curves than the flat came of the same width.

The technique for finishing a curve around a single piece of glass is given next.

8 - Leading small circles

Putting came around small circles such as lenses and small bullions often leaves an irregular curve. There is a way to avoid this.

Use oval or round came to reduce the kinking of the leaves of the came. As there is less material at the edges of the leaves of oval came, there is less kinking than on flat came, where the thickness of the leaves is constant.

Begin to form the lead round the circle, about half way. Then take the circle out of the came and cut, at a right angle to the length of the lead, at an angle from top to bottom. The degree of the angle is not important at this stage, only that you can repeat the angle – so it must be fairly shallow and natural for you. 

Put the circle back into the came and continue to form the came round it until you meet the angled cut at the beginning. Again at right angles to the length of the came, cut a repeat of the angle.

Then fold this end toward the other end. Push the two angled ends together. If they slip up and down from each other, the came is too long. Open the came and cut a sliver off. 

Try again until they meet with very little “slippage”.

Then the piece is ready to put into the panel. Place the join at a lead joint so you don't have an additional solder spot.

This technique can be used for small ovals too.

9 - Leading Nuggets
This is a special case of leading small circles. To use nuggets in leaded glass panels, just wrap the came round the nugget. If the came leaves are oval, it works better than the flat. If the nugget is thick and does not want to fit securely in the channel, you can also use a fid to open up the top leaf of the came.

10 - Leading tight curves

When leading tight inside curves, it helps to bend the came into a tighter curve than is needed for the glass. Then roll it into the glass. Finally, run your fid or stopping knife along the heart of the came to ensure it is firmly against the glass. All this helps the came to fit snugly into the curve.

11 - False Lines in Leading

False lines are used in leaded glass where the design calls for an angle that cannot be cut into the glass. This includes right angles and even more acute angles. E.g., the petals of a fuchsia flower. The design would call for an angle of about 60 degrees. This is impossible to achieve through cutting. So the glass is cut in a curve and the cames on the side and bottom of the petal have their hearts cut out so they overlap each other. The overlap is then trimmed to the shape of the outside of the petal. When soldered, the appearance is of the glass being cut at the angle required for the flower.

At other times, the requirement is for a line to go into a piece of glass, but not all the way across. Again you cut the heart out of the came, and overlay the smoothed lead onto the glass. You can use just a little silicone to hold the lead in place until you finish cementing. After this you can lift the piece of came and use silicone or epoxy resin to firmly attach the came to the glass. You do not want to do this before cementing as any excess of glue will be made dirty by the cementing process and be very difficult to clean up.

12 - Silhouettes in leaded glass

There are times when you may want to have a silhouette. You could use a dark piece of glass, or if it is a complex shape you can cut it out of lead foil or thick copper foil and solder it into place. This allows intricate shapes to be made when a dark representation of the shape is required. If the panel can be seen from both sides, the overlays should also be on both sides. These should be glued to the glass just as for cames.

These principles can be applied to copper foil too.

13 - Sculpting the came

It is not essential that the came always have parallel edges. In some cases you may want to have tapering cames to represent perspective. This can be done simply by trimming the flanges of the lead so it gradually thins, possibly to meet a thinner lead at a joint. Both sides of the lead came need to have the same trimming. You can also create an irregular shape to the edge by carving out portions along its length. The permutations are numerous.

In all these cases this should be done after soldering but before cementing, as you will leave a track of putty at the previous edge which will need additional cleaning. Of course, if you don't mind that extra cleaning, you can do the sculpting after cementing, but probably before polishing, so any scratches from slips of the lead knife can be polished out in one operation.

14 - Copper foil in leaded panels

It is possible to combine copper foil in a leaded glass panel.

The copper foiled piece should be soldered before inserting it into the lead came. In this way the soldered together pieces become very like another piece of glass.

There are some special considerations, of course.

The copper foiled piece should be designed as though it were a single piece of glass and so can be accommodated into the surrounding pieces of glass.
The copper foiled piece should not have severe undercuts which would make it difficult to insert into the surrounding glass. It may be necessary to incorporate a piece of the surrounding colour to make it fit into the panel.

The copper foiled piece should be finished with all the beads on both sides. If one side is left flat, it will collect water if on the outside, and catch on any cleaning processes whichever side it is on. However, the piece should be tinned only on the outer edges. This will ensure that the copper foiled piece will slip into the came.

The image below illustrates a copper foiled piece incorporated into a leaded panel.

This section of the panel shows the accommodation of the main leaded panel with the copper foiled piece with a line from a petal to a leaf. Otherwise, it was fitted as one piece.

Friday, 18 May 2012

Design Principles for Stained Glass

  1. Designing for Strength
  2. Responsive Colour selection
  3. Beautiful Design Lines
  4. Design Sources
  5. Reworking Designs
  6. Some practicalities
  7. Conclusion

There comes a stage when each of us moves from using patterns developed by others to trying to realise our own vision. This is the time where, in attempting to reproduce an image from our mind or from natural and man-made forms, that we begin to encounter difficulties with the medium of glass and lead or copper foil.

There are a number of principles that should be kept in mind while designing, or at least referred to when the design is reaching its final stages. This article is an attempt to outline a number of the most important points in designing glass panels, especially larger ones. It also includes some practical applications.

Designing for Strength
Principles of Design Practice for Stained Glass, 1

The panel needs to be strong to last for a long time. Glass is a very resilient material; so is lead and solder. It would be a shame to design a panel in long-lasting materials that will not survive for long because of the design and construction. There are some things to remember about creating a strong panel.

The strength of a panel is in its glass

Glass in compression is stronger than steel. It is only when it is in tension that its weakness - or fragility – becomes apparent. So the structural arrangement of the glass needs to be such that each piece of glass supports its neighbours. It also needs to use shapes that are strong.

Avoid the following shapes:

Hour glass shapes – those where the ends are wider/larger than the middle - are very likely to crack at the narrowest part. If the shape – usually a negative or background one – is necessary, break it up into smaller pieces that make sense in the whole design. It is also possible to add details that will break up these shapes, but be careful that the details do not detract from the whole.

Exaggerated, deep inner curves will eventually crack at apex of curve. If unavoidable, you should consider adding design lines where the glass would break anyway, or moving elements closer together so they almost touch to avoid the single deep inner curve.

Thin long and tapering glass pieces are very likely to crack near the point or be covered by the lead or copper foil. Where you need to have such shapes, try drawing the lead or copper foil lines on the design. You can do this on a piece of tracing paper to avoid messing up your original design. This will show you how the finished panel may look. Alternatively, you can divide the long tapering piece of glass into several pieces so that any flexibility of the whole panel does not break the long thin piece. Short thin pieces are not so likely to be broken by any movement of the panel.

Inadvisable design elements

Lines radiating from a single point also provide weak areas because the glass is divided into long thin pieces which are liable to breakage. Break up long thin pieces of glass with suitable lines. This ensures that the length of the glass is in a strong relationship with its narrowness.

Avoid “hinges” - lines that run from edge to edge (vertical, diagonal or horizontal) – as these provide places where the panel can bend. This is why windows made up of rectangular quarries need so much support and even then over time begin to concertina. Even if the lines do not run all the way to the edge, any significantly long line will put pressure on the glass pieces at the ends of the hinges, for example, a series of formal border pieces or narrow central pieces. A hinge will be a weakness in the long term whether it survives the studio processes or not.

However, we all have seen leaded glass windows with single or multiple hinges that survive for many decades, and only as they loose support from firm cement and the ties to the saddle bars break away, does the panel begin to self destruct. It is important to recognise where these hinges are to be able to place reinforcements on the panel. But the real solution for making a panel that will last, it is best practice to avoid designing hinges into the finished work.

Avoid complicated shapes

Don’t over-complicate the cut lines. This makes for difficulty in cutting the pieces. Also the more difficult it is to cut the pieces of glass, the more likely it is to fail by breaking after being installed.

Responsive Colour Selection
Principles of design practice for stained glass, 2

The graphic form of much stained glass means that the medium is largely about line and colour. This requires that you think about both your and the viewer's response to the colour combinations. Respond to your instincts. Use you feelings about colour and their relationships. Try different colour ways. Formal training does help, but experience develops your skills. The individuality of the piece depends on the use of your instincts about the colour. There are some checks you can make while selecting colours.

Think of colour and impact.
Hot colours tend to have more impact, as they give bright points or areas. Impact can also be created by using non-complementary colours together. If a more subtle impression is desired, use tonal variations without great contrasts.

Vary areas of colour and their proportions.
This provides interest to a panel. It avoids a mechanical symmetrical appearance, even if the design is symmetrical

Think about colour balance.
Although the colours may vary it is important that the weights of the colours are balanced so that the focus of the panel is not lost to another part because of the imbalance of the colour with the design.

Get some distance.
When you are in difficulty selecting or arranging the colour, step back and view from a distance. This is one of several techniques to enable you to get a larger or different view. Others include viewing the design through a mirror, viewing through half closed eyes, look at the design from the other end, and viewing the design from acute angles.

Use your instincts.
When something feels wrong, trust your intuition and use other colours. Colour theory is just that -theory. It is through using your reactions that the piece becomes individual.

Seek out the nuances of the glass.
The tones and textures alter the perceived colour and weight considerably.

Simplicity of line.
Keep the design lines simple when your emphasis is on colour, light and texture. This allows those qualities to dominate the panel, rather than the lines.

Coloured drawings
Always make a coloured drawing before choosing the glass as a reference. This is a rendering of your original idea. It provides a reference as you select the colours. It is something that can be altered, of course, but does provide an essential reference point.

Use the same light as the installation location.
Choose glass colours in the kind of light for which the panel is intended. This is essential, as the glass colour is subtly different in daylight, incandescent, and fluorescent lights.

Be bold in your choices of colour.
Glass artists need to be very aware of light and dark, both in terms of colour selection and in terms of density. A very thick dense glass of a dark shade of any colour will create a much more intense darkness than glass that is thinner and less dense.

Represent the light.
In terms of colour, lighter hues go where the sun shines or where the eye is to be drawn. Pastel shades also indicate brightness and light. This also can be achieved by using the pale opalescent glass to indicate where light is falling.

Represent the shadows.
A denser dark glass can be used to indicate where light does not fall, or where very little light can filter through. It can also play the part of negative space. It is also possible to consider double plating areas where more darkness is needed.

Of course, vitreous paints can be used to control the amount of light in very subtle and realistic ways.

Use chiaroscuro.
This word - borrowed from Italian ("light and shade" or "dark") - refers to the modelling of volume by boldly contrasting light and shade. These contrasts between light and dark can be used in several ways. Darkness can indicate depth of field or distance when used in a general landscape. Or, it can be used to bring a foreground out, making other elements more vivid. The key thing to remember in using stained glass is to not be afraid of dark glasses. They can very useful, even if of very odd hues of colour.

Beautiful Design Lines
Principles of design practice for stained glass, 3

Stained glass is a graphic medium where line and colour are very important. Achieving pleasing lines and forms requires practice and use of various approaches and techniques.

The two dimensional world is one of abstract thought. Work and development are the way to creativity – there is no mystical talent. Practice drawing every day – set aside time to do it, if you normally shy away from drawing as an exercise.

Study and learn from what has gone before. Look at the images and objects you admire and analyse what you like about them and why. Also consider what things could have been done differently. Consider how those changes would affect the character of the piece.

Of course, maintaining your creative attention is difficult, so when blocks occur try some or all of these things:
  • Put the work aside for a day or two before taking it out and looking at it again.
  • Alternatively, pin up the design on a wall where you can look at as you pass by. When you see a change to be made, do it immediately and pin it back up

Get a new perspective, e.g.:
  • Turn it upside down. This will enable you to observe differences and spot inconsistencies
  • Look at it in a mirror. You might see people studying still life or live subjects together with their drawing in a hand mirror to get a new perspective that will help spot difficulties.
  • Put the design on the floor and climb a ladder to look at it. This provides distance and changes the angle at which you look at your design.

Remember that design tends toward realism or abstraction. You need to work on both forms, remembering that glass is a graphic medium that tends toward abstraction. Working on both forms develops your flexibility and knowledge. Having a working knowledge of both enables you to have a responsive approach to the client.

Design Sources
Principles of Design Practice for Stained Glass 4

Use the everyday visual experience and make interpretations and adaptations. E.g.,
  • draw lead lines on an illustration to make it suitable for stained glass, using the fewest lines possible
  • Use your photographs of interesting subjects and scenes

These may never become useable designs or cartoons, but will increase your abilities to design from the real world toward the abstract.

Make and keep sketches as personal references. These do not need to be finished drawings, just a reminder of the thing(s) that caught your eye. Many artists always carry around a notebook to record these observations. Even if you only make drawings on paper napkins, make a folder to keep these separate sketches together.

Take photos of shapes and interesting images. These can then be used later to develop images.

Make up composite images by using overlays or collage. This helps develop your compositional abilities.

Work on abstraction in your design practice:
  • Study abstract representations. Dissect – decomposition is a popular word - and analyse how the work is put together.
  • Use geometric design as an introduction to abstract design. This forces your attention to structure, balance and colour.

Once the distribution of the physical and visual weights is understood, this enables the jump to more free forms of abstraction.

Reworking Designs
Principles of design practice for stained glass, 5

Having created the design, you should consider re-working the designs for a variety of reasons. Some of these are:

  • to save time in the later stages of the work. It all too easy in the excitement of creating a new piece to want to get directly on with making, however this often gives construction or design difficulties that have to be solved in the making, leading to compromises. In general far too little time is spent in the design stage. Time spent on the design will be more than saved in the construction and will produce a more satisfactory piece.

  • to ensure the structural stability of the piece. Although reinforcement should be considered from the beginning of the design, this is the time to ensure that the piece will stand up to the use it will receive during its – expected – long life.

  • Make sure the design is still structurally sound. The design should avoid long nearly straight lines with few interruptions, especially those that go from edge to edge in any direction. The lines should interlock rather than have many joins onto long lines.

  • To make sure you have investigated every possibility to answer the challenges of your design.

  • Reworking will enable you to maintain the essence of the design while simplifying lines and easing the labour of the construction of the panel. Often the design contains a number of lines that are not essential to the whole design.

  • As you re-work the design, you can make sure every curve, dip and angle are to your liking and so improve the whole. Redrawing also helps understanding of the design and the placing of lines. It will also help in considering the placement of lead came and the widths to be used.

  • It gives an opportunity to ensure that you can cut all the pieces. This is the time to look at the negative or background pieces to make sure you can cut them as well as the foreground pieces. Usually people are so concentrated on designing the main image that the background becomes too complicated to cut easily.

Make successive tracings with each change, so there is a record, allowing you to step back wards to an earlier version if necessary.

If this re-working stage leads to the realisation of design problems, there are some things that can be tried:

  • Cropping the design can transform it. The focus of the design can be enhanced by removing some of the surrounding “information”. The change of proportions say from landscape to portrait can make significant differences.

  • Enlarging and using only a portion of the original design can be a solution. This is similar to the cropping operation, but has the added advantage of making the pieces larger and easier to cut.

  • Further simplification of background design lines can be considered. This will bring the focus back onto the main part of the image.

  • Changing relative proportions can transform the design, e.g., by enlarging a busy background, it can be made simpler and easier to read the whole panel.

Some practicalities
Principles of Design Practice for Stained Glass 6

The traditional approach to cartoons meant three versions were necessary. One with all the drawing details, one with the cut lines, and one for layout and leading.

If you are doing a leaded or copper foiled panel without details for painting on glass two copies are the maximum required. I make do with one original, as I have no place to keep the glass pieces laid out while cutting and beginning to lead, nor do I make templates for cutting unless absolutely necessary.

The paper you need is one that is stiff enough to avoid changes in shape or wrinkling with changes in humidity. The paper also has to be robust enough to stand up to lots of movement. Cartridge paper from a roll works well, but is often seen as expensive. Brown wrapping paper is usually stiff enough, although thinner than cartridge paper. If your design is narrow enough, you can use lining wallpaper.

Tracing paper is very useful, if you do not have a light box, as you can trace details from one version of a cartoon – whether new or from an old one – into another. However it changes shape when exposed to high humidity. To transfer the cartoon to more stable or more opaque paper, you can use a pounce wheel to transfer through the tracing paper for the final cartoon.

If you have a light box you can use it to make the transfer, or you can stand at a window with the two sheets of paper taped together to trace the design onto the final cartoon paper.

If you need to make pattern pieces you will need a second copy of the cartoon to cut up. Here you need paper or card that lies flat. You may also find it useful to cover the main cartoon with a water proof covering if you are going to do a lot of grinding and fitting over the cartoon. You can do this by oiling your paper (as for stencils) or by sticking clear vinyl over the cartoon.

Transparency sketches

Use matt finish acetate .25 to .12mm thick. This will later be fixed to Perspex for presentation.

You will need rigger brushes in sizes 0, 1, 2, and 4 for doing the lead lines and other areas of graphic delineation. In using these brushes for lead lines, you want to maintain a line that is consistently thick. It is a different feeling from general image making and you may want to try locking your wrist to maintain a greater consistency of pressure.The paint for the lead lines can be a calligraphy ink or a black acrylic paint. The lead lines and all other tracing is applied to the matt side of the acetate.

Once the tracing lines are all completed, start laying the colours on the backside, the smooth side. The brushes to use are bulbous pointed sables in sizes 2, 3, 5 and 6. The application is in a "floated" versus a "stroked" manner of application. Stroking has a tendency to hasten the drying resulting in streaking. You may find this a bit of a trick at first. It is advisable to place colour throughout the design so it has time to set up and dry a bit, as opposed to putting wet against wet.

When the colour has dried, you can emulate matting on the matt side with an ebony pencil. And if you want to take out some lights, that can be accomplished with carefully placed extender. The extender is also used to make the piece transparent and to emulate a variety of textures available in glass from reamy to seedy.

When the colours are dry, mount the sketch on 3mm Perspex to stiffen the presentation, provide weight and give the presentation with some "substance”. You can also add double matt board doors hinged with smooth electrical tape to keep the lacquer colours away from sustained sun. Also when open, they support the sketch during the presentation.

When putting matting boards around the presentation sketch, they should be much wider than the drawing or water colour so that ambient light from behind is modified by a greater expanse of black or dark matting board.

"Transparency sketches" edited from emails by Richard Millard

There are, of course, a number of CAD and drawing programs available for computers which can be used to make presentations to the clients. However, I have no experience with them, so perhaps some one will give pointers on how to make use of these electronic means of presentation.

Cartooning for acute angles

When you are moving from the sketch design to the cartoon lines for panels, you can prevent some leading difficulties. If you have shapes that join at acute angles, you can alter the cartoon lines from the design to make the leading simpler.

Say you have two balls touching in the design. You can continue the design of the cartoon so the cut lines intersect or touch each other. This makes for extremely acute angles in the cutting of the cames. Two balls touching in the presentation drawing will not look the same if leaded that way. Therefore, make the edges of the balls just a few millimetres separate in the cartoon, and the cames will pass each other, just touching, retaining the appearance of the presentation drawing, rather than the appearance of overlapping.

To do this, you separate the lines by the thickness of the came you will be using for that area. If you are using 6mm came, the cut lines should be just less than that distance apart. This will allow the cames to go around each shape and the flanges of the came will just overlap. This makes for quick leading and a clean appearance.

Making copies

Using a photocopier is not always the best way to provide copies or reproduce the cut lines. At significant enlargements, there is distortion of the lines and the cut lines are much too wide to be practical cutting guides. A much older instrument useful for this kind of reproduction is a pounce wheel. These are still made and are available. The pounce wheel comes from a time before photocopying or carbon papers. It gets its name from its use together with a pounce bag. In the past the pounce wheel would make holes through the paper or card along the design lines. The paper or card is put over the material which is to have the image copied onto it. A small bag of black powder would be dabbed (pounced) on the cover paper leaving black dots on the surface below. These could then be used to trace the same image many times on what ever medium was being used.

To copy part of one stage of a design onto a new one without using tracing or carbon papers you only need to layer a new sheet of paper under the current design and run the pounce wheel over the parts you want to copy. As you move the wheel along, it punctures the top layer and into the lower layer. Normally, the puncture marks are all that are needed to be able to reproduce the original lines.

You can also use the wheel to create mirror images by running the pounce wheel over the card, turn the card over and draw using the puncture marks.

You can get symmetrical images too, by folding the paper along the centre line and running the pounce wheel over the existing line. Unfold the paper and use the puncture marks to make lines symmetrical on each side.

Avoid tapering pieces in the design.

You can't use long tapered pieces in larger panels, without modification for the structural reasons outlined previously.

Also you can't make a neat termination by joining half a dozen tapers at one point. Your piece will not look exactly what it looks like when you drew it out with a pencil. You can pencil in a termination with six points, ending at one place and it may look good, but try drawing it in with a felt tip pen almost 6mm wide, which allows for what solder or foil will cover, and see what that point looks like then. You won't be pleased with the large blob at the termination.


No one can teach one easy fix for everything you will encounter, so the answer starts with the design - before you cut and foil, or fit the came to the glass.

Art is not about the physical placement of what you see in your mind, as much as it is about the "illusion" you are creating that you want others to see. That starts with the design, and avoiding something that you know is going to give you a problem in building or viewing the final piece.