Glass-on-Glass Screen Printing
The Process
Take a digital photo of an image with good contrast and a story to tell. It doesn’t need much resolution because it is going to be printed by pushing powdered glass through silkscreens. Using Photoshop, strip all the color out of the image, leaving just three to five levels of brightness: white; one, two, or three shades of gray; and black. For a white-on-black print (white powder on black sheet glass), save each gray layer and the white layer as separate images and send them to a specialized shop that prints stencils – very thick, dark black ink on transparent plastic film for burning images onto silkscreens.
Image the Screens
Coat each screen with emulsion and let them dry completely. With a light box, burn the stencils onto silkscreens and spray out the image with a power washer, leaving the screen fabric uncoated where the glass powder is supposed to fall through. Here’s a short post with a video clip of coating a screen.
Pull the Powder
Cut a piece of sheet glass for the background and lay it on the work surface. Place the first silkscreen about 1/4″ above it. Squeegee the powdered glass through the open areas of the silkscreens. When printing ink on paper or fabric, you only make one pass per stencil with the ink and squeegee, but for glass powder, it takes several passes. The number of passes depends on multiple variables, so you need to try one or more little test pieces before committing a large piece of sheet glass and lots of powder. This video clip shows me pulling powder. The process is repeated for each layer of the image, carefully aligning the screens with the powder that has already been applied.
Fire It!
VERY CAREFULLY, move the piece into the kiln and bake it at something between 1000 and 1500 F. For white-on-dark images, the white powder should only be allowed to get hot enough to make it stick together. If it melts, it becomes almost transparent. For dark-on-light or colors-on-white pieces, the piece needs to be fused to a higher temperature so the powders melt and reveal their true colors.
Completed Glass-on-Glass Screen Prints
Little Boy, Big Jungle
I spotted this small boy in the trees and undergrowth along a rural road near the coast in southwestern Haiti. He appeared to be alone, and may have been picking bananas or other wild-growing fruits to eat. Image: Four shades of green and three shades of orange powdered glass pulled through six silkscreensFrame: Many thin strips cut from green streaky sheet glass standing on edge, bordered by strips and squares of black sheet glass, all kiln-fused onto white sheet glass…
Burden
Women and children carry laundry to the river. Their burdens are portrayed as American flags to represent the treatment of Haitian people by more powerful nations over more than five centuries. Image: black, green, and two shades of gray applied with four silkscreens and kiln-fired. Red and blue glass powders added by hand and fired. Background: white sheet glass
Basket Maker
A village elder carrying her supplies for weaving hats, baskets, and other items to sell. Image: White powdered glass silk-screened onto black sheet glass and lightly kiln-fired. Frame: fused mosaic of tiny squares of sheet glass, standing on edge and fused onto the sheet glass background. Frame is completed first, then the image is screened onto the background and very lightly fired. This was my first photo-based glass-on-glass screen print. I had taken a class on screen printing with powdered…
At the Well
Women and girls draw water from a hand-pumped well in Les Anglais, Haiti. When wells aren’t available, or are broken from continual use, people walk for miles to collect water from polluted rivers for drinking, bathing, cooking, and washing, resulting in many dire illnesses. Children are often the ones to make the long trips for water, keeping them from full attendance at school. Walking around the town, we would find every well in use, with people waiting in line. It…
Mending a Net
A young fisherman in front of his home repairing a net. He lives in the “beach village” near Les Anglais, Haiti. People who can’t afford to own or rent property build huts and shanties on the beach that are always at risk from storms. Image: Glass-on-Glass screen print using four silkscreens for the four shades of grayFrame: fused sheet glass
Shadow Berries
Small berries remain on winter bushes along a street near the State Capitol building in Santa Fe. The red glass bits used for the berries were tack-fused on after the black and gray powders were fired, so they would maintain their shape and sparkle. The white glass background is slightly translucent, so an LED “candle” lit behind it makes the piece glow. Gray and black glass powders were screened onto white sheet glass, black glass powder was screened onto a…
Santa Fe Shadows
Late-afternoon shadows along Paseo de Peralta in winter. I blended a mix of powdered glass colors to approximate the color of the adobe surface.
Three Chairs
The photo for this piece was taken across a small lake on Newfoundland. Most of the image is powdered glass, applied with silkscreens, and fully fused onto the glass background. The leaves on the trees are small, sparkling chunks of glass that were added by hand later, and fired just enough to become slightly rounded and stick to the piece.
Pinon Plateau
Early morning at the end of a trail in Arches National Park
Panorama
Distant bluffs in Arches National Park, photographed from the back seat of a moving motorcycle.
Fiery Shadows
The photo behind this glass-on-glass screen print was taken on a winder night in Ashland, Oregon. It is the shadow of bare branches on a sidewalk under a street light. Instead of gray powders for the lighter shadows, I used red, yellow, and orange powdered glass.
Havana High-Rise
Richard Glenn, a friend and fellow Pacific Northwest Glass Guild member, took the photo behind this piece in Cuba. As soon as I saw it, I knew it had to become a screen print, and we agreed that I would use his photo to make glass prints and the first one would be his. Someday, I hope to make a version with bright colors for the flowers and leaves of the plants on the balconies. This print required four silkscreens…
Street Market
This is the main road through a village that our teams always looked forward to seeing as we drove from Port Au Prince to Les Anglais, on the southwest arm of Haiti. I don’t think we ever drove through here when the road wasn’t crowded with people and products. For this large piece, the blacks and grays, blue sky, tan dirt road, green palm leaves, and rusty tin roof were each printed with a different screen. To make sure I…
Pulling Glass Powder
Demonstration of pulling powder across a silkscreen as part of making a glass-on-glass print.
Watch Me Coat a Silkscreen
This short video shows how fast to slide the emulsion trough. Be sure you have your speakers on to hear the sound that tells you your speed and pressure are good.