May 2020 Stained Glass Design and Glasspainting Workshops

In response to student feedback I’m offering a series of three tightly structured 5-day workshops in May 2020. Two are for advanced students only and designed to take your stained glass practice to a new level.

Instruction includes Powerpoint presentations, technical demonstration, hands-on group exercises and individual projects. In these workshops I will teach practical skills and repeatable, step-by-step processes that are difficult to learn online or figure out on your own. For example, mixing glasspaint to optimum viscosity and drying speed for various tools and brushes; and gaining a clear understanding of the work-flow for designing or painting a stained glass window.

Here’s the history of my proprietary stained glass recipe, and here’s my beautifully responsive glasspainting mixture in action

Workshop location? Watch me glasspainting and assembling a stained glass window in my Vermont studio where these May 2020 workshops will be held  (11 min video).

About me? This recent podcast covers my career as a stained glass artist and includes the mathematics I’ve been working on in recent years. Many thanks to interviewer Shawn Waggonner, she really got me to open up!

Check out the drop-down menu items under GLASS to read workshop descriptions and more.






Choosing skin tones; Where to start?

Where to start?

People often ask me where I start selecting glass. Is it the bottom left-hand corner? Or do I dot around all over the place and choose all the greens first?

Generally, I either start with an area where I am absolutely sure of my choices, or an area where I’m not sure but the colour plays a crucial part in the composition.

Here, it was the sea and the sunrise that were key. I have never made a landscape like this before, and I really wanted to create a sense of distance and the effect of light on the horizon. I rarely use streaky glasses where the colour is irregular (As Patrick Reyntiens once said to me, the striations “.. tend to quarrel with your glasspainting.”) but I really wanted pink skies, and softer pink reflections in the river too. So I broke my own rules and bought a sheet of streaky pink/amber/clear glass for the skies, and a smoky blue for the sea that faded lighter towards the center.

Once I had chosen these the rest of the landscape followed along behind – softer colours in the distance, brighter towards the foreground. The sky/sea colours provided me with a starting point for the colour intensities (bright or muted) for the window.


Note that the blue colour on the top right in this photo (behind the seagull) is the real sky outside my studio, there’s no coloured glass there yet. This is one of the delights and challenges of stained glass; working with a medium that keeps changing on you. It’s like painting with shifting sands. Here’s another photo taken a few days later with bare trees behind -it looks completely different!


Selecting skin tones

Selecting skin tones in a pictorial window is also pretty crucial, and I tend to use the same method. In this case, there was only one glass I could use for the kneeling man on the right. The Committee had asked me to make him bareheaded with a not-too-modern haircut, and elderly. I decided, for the first time, to use flashed glass to give him really white hair. Flashed glass has two layers of colour, one of which may be removed by acid etching or sandblasting. In this case, I bought a sheet of Lamberts 1032 that has a thin skin of beige (the flesh colour) that will be removed to reveal the clear underlayer for the hair and beard.

I suppose I should point out that, in my medieval-style stained glass, the paint is black. All the colour you see is in the glass itself. If this seems a little confusing you can watch the entire process condensed down into two lovely short videos, Menfolk Part 1 (6 mins) and Part 2 (7mins).

Any way… once the skin tone (and ethnicity) for the old man was settled it provided a fixed point for choosing the others. The most challenging was probably the little Chinese girl’s. I didn’t want her to look jaundiced, so gave her a turquoise dress and chose a deep greenish grey for the boy’s robes behind (and right next to her skin) so as to pump a little more warmth into her complexion.

The amber colour behind her is perhaps the least helpful contrast, but the little girl’s hair will be painted black, so the colours won’t seem so close. If you’re lost here too, check out this site to learn about the effect of adjacent colours on each other.

It’s a curious thing, selecting glass, and all the while imagining how the window will look when painted and assembled. Eventually, the glasspainting will bring all these different colours together into one seamless picture. It’s quite a magical process really.

Selecting colour/glass the English way, and why.

Q What sort of glass am I working with?

I use mostly Lamberts mouth-blown glass, hand-made in Germany. There is only one US distributor, S.A.Bendheim and two warehouses, one in California and the other, fortunately for me, in New Jersey. It’s a marvel to watch these glassblowers make huge cylinders of glass and maneuver them around so skillfully. Watch a video. I also use various other types of glass whenever necessary to achieve precisely the colours I am after. I’m not a purist.

Q How do I fix the pieces of coloured glass to the easel plates and why?

I use a type of modeling clay called Plasticene to fix up the pieces of glass. This is the way I learned as a young person whilst working for Goddard & Gibbs, the UK’s biggest stained glass studio. Plasticene (or Plastilene in the USA) is applied like thumb wax. It’s a bit greasy but great because I can remove pieces if I need to make changes. It may take several attempts to get precisely the correct colour and value/tone, especially in a pictorial window like this one. Here’s how the easel looks in reflected light, with all the blobs of Plasticene and some strips of clear packing tape over the top panels for good measure.


Every piece of glass affects and is affected by it’s neighbors, so the overall composition evolves as you add new colours. Stained glass is basically collage (i.e., you cannot mix the colours) but there are subtle ways of managing how colours appear by choosing neighboring pieces to shift a colour’s temperature, intensity, or to make it appear lighter or darker than it really is.

Look at the outstretched hand of the woman below. It is cut from precisely the same glass as her face but it looks too dark because it’s surrounded by so much pale blue. I’ll have to change it.


By the way, the woman’s shawl is all cut from the same sheet of glass too (though not the same sheet as her face). It’s one of my favourites (Lamberts 20-1067) that transitions from pink to peach to orange across a single sheet. I love using different areas of the same sheet in close proximity because the colours harmonize so beautifully.

I’ve been choosing subtly cooler colours for the far right of this window (bluer greens, silvery grey in the river, etc) and staying warmer to the left, hence the warm glow on her headdress. Here’s a video about my work for St Henry Church in Nashville that describes my glass colour selection process in more detail.

Q Why do I choose my glass in this laborious fashion?

I realise that many people select their glass on the light table but I find this pretty challenging. Colours do not appear accurately. The lightbox is uneven, so it’s hard to read tone/value. I cannot read the texture of the glass accurately because it appears flat and opaque, whereas at the easel it sparkles or ripples with light. Although I paint and fire pretty much every piece of glass in a window, I’ve developed methods that maintain pure transparency almost all areas, so the liveliness of the glass is not lost. Manipulating transparency is one of the true delights in making stained glass.

Colour/glass selection is a key part of my process. These slides show how the cartoon, cutlines and glass selection all come together in the end.

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They show work-in-progress on a 25ft window I designed, cartooned, cut and painted for Marble Collegiate Church on 5th Ave in Manhattan. Rambusch Decorating Co did the fabrication and installation in 2002. Thankyou Martin Rambusch for giving me such a great opportunity.

My new blog! selecting glass & cartooning for Trinity Episcopal

I’ve started this blog to answer questions about my work; to allow clients to watch the creation of their windows (welcome Trinity Episcopal); and to let everyone know that this beautiful medieval art form is still alive and kicking! Since I find it easier to respond than to write afresh, please ask away and we’ll see how it goes. It’s a blog experiment!

Today I have been selecting and cutting coloured glass for a figurative window for Trinity Episcopal Church in Branford, Connecticut. I choose the glass one piece at a time up against natural light, comparing it with all the others as I go. My easeling window faces north with trees and mountains beyond. I’m always grateful to complete the glasscutting stage during the winter against snow and bare trees, where the only colour distortions are from blue skies. Watch a slideshow of the glass selection for Trinity Episcopal in progress.


Some weeks back I presented the cartoon to the Church for Approval. The ink & charcoal cartoon is a full-scale black and white working drawing that provides me with all the information I need to make a window. Watch a slideshow of the cartooning for Trinity Episcopal in progress, including photos of models and some of the revisions.


If you’re wondering how visual information from the cartoon is prepared for glasscutting you can watch a slideshow of the cutlining for Trinity Episcopal, and my assistant, Sam Myers, inking in cutlines and marking up easel plates.

Here’s the design, presented to the Church last August.

Design copyright Debora Coombs 2013