Frit is crushed colored glass ranging in size from fine powder (about like superfine sugar, maybe a bit finer) to coarse flattish chunks about the size of a hazelnut.
You can draw with it, decorate with it, mound it and tack-fuse it into crystalline structures, pack it into a mold and make watercolor-like vessels, carefully place different colors into molds and cast it as pate de verre, paint it onto multiple layers of clear glass, stack them and fire deep (as Bullseye’s Painting with Light” method), cast it into trays to make panels with remarkable, layered depths, mix it with a paste or gel to turn it into “paint” you can apply with a brush or pastry bag, or mix it with a thicker gel to make moldable “clay” out of it.
They’re incredibly useful references for figuring out which colors of frit will do what, and how they’re likely to pack down.
Powder, for example, usually loses about 50% of its volume at full fuse, but at tack fuse the volume reduction is (not surprisingly) proportional to the degree of fuse. For most of my tack fuses it seems to be about 25%; this info is useful when I’m trying to cover the margins of an area–it tells me how much overlap and thickness I’ll need.
It also turns out that they’re pretty attractive on a wall (well, what’s the point of making reference samples if you can’t stand to look at them?), and much in demand from friends and relatives for presents.
I make them with a flat piece of glass (thin or 3mm, whatever I have on hand), then cut thin strips of clear, lay them on the base on edge, and superglue them in place.
I work on a grid system, pretty much putting in dividers until I run out. Then I fill them as I have time and ideas. When one fills up, I tack fuse it (the degree of tack fuse depends on what I’m experimenting with, but it ranges from about 1275 to 1325 (degrees F) for anywhere from 10 to 20 minutes).
When they come out, I stick a clear hanger on the back, hang them up and start looking for effects I like. The tactile quality is probably most pleasing to me–you really do want to rub your fingers all over these.
I particularly enjoyed one experiment–packing powder into simple geometric shapes and letting it fuse into glossy pyramids and circles and squares. So, just as fun exercise, I decided to do a whole piece this way, with a few twists. I built the tray but instead of using clear glass, I used a combination of thin black strips and 3mm gold-irid-on-black squares, laid flat.
Then I’m mixing up various combinations of Bullseye Carnelian, Marzipan Striker, French Vanilla, Medium Amber, Ivory, Lightning White, Coral Orange, Clear…all kinds of neutral powders including an Uroboros powder I especially like, Sand Opal, and packing them into the cells in a pyramid shape.
I’m topping them with slightly coarser fine frit in related colors, and adding one pyramid in Turquoise Blue, for interest. It comes out sorta looking like frost on the lawn on a fall day, or maybe sugar sprinkled on top of dessert.
I fired the piece last night, using a modestly conservative tack-fuse schedule. The powder most likely won’t cause many stress issues (and in the polariscope, it didn’t). However, the strips retain their shape and are hitting the base glass at 90 degrees, so they have a pretty good potential for stress.
The final came out tonight–it’s at the top of this post. Here’s a closeup of the pyramids–you can see how much they pulled back from the edges of the cells.
Ain’t exactly a masterpiece, but it was a fun exercise. The different combinations of neutrals that make up the pyramid will be useful for figuring out other tack-fuse combinations.
I need to do some additional experiments with this–some very cool possibilities here.