Reading a tile
What the numbers mean
Two of these get asked at the slab roller every day we are open, so they are the big ones on every tile.
Clay to start with
That is what to pull off the bag, not what the finished piece weighs. You will trim a fair amount off the edges, and every scrap goes straight back in your bag. Running short halfway through a slab is the one mistake you cannot fix, so these numbers round up. Beginners should add 30% until the slab roller stops surprising them, and the switch above does that math on every tile at once.
Slab thickness
One third of an inch for slab molds with a footprint under 8 inches, half an inch for anything bigger, three quarters for the three colossal ones. The slab roller gauge is marked in eighths, and the half inch setting already counts the mats. Rolled too thin, a big piece warps in the kiln.
Mold volume
An educated guess worked out from the shape of the mold itself, not a measurement of a finished piece. A real pot is thicker in some places than others and the clay moves in the kiln, so read this as a size class rather than a number to plan around. Depth is the softest of the three dimensions, so allow give or take 15%.
Plastic wrap
Plaster and fiberboard pull water out of the slab, so the piece lets go on its own. Ceramic, metal, stone and sealed wood do not. Those 27 molds get wrapped before the clay goes on, or it sticks and tears coming off.
Companion and sister molds
Companions are the same shape in other sizes, for building a graduated set of one thing. Sisters are different shapes at a similar scale, so a table of them looks planned rather than collected. Both chips jump straight to that tile.
Shelf numbers
Shelf 1 through 9, the closet, or hanging on the wall. Open the Description on any tile and the shelf is the first thing in it, so nobody has to walk the Mold Room twice. One mold out at a time until you know where everything goes.
Green Level, 5Yellow Level, 29Purple Level, 35Black Level, 3Owner Only, 3
Black Level molds need the owner alongside you the first time you use one. The colored sticker on the underside of a mold is what sets the level. If a sticker and this page ever disagree, the sticker wins, and it is worth telling the owner so the page can be fixed.
The slab roller and slab mold training takes about twenty five minutes, fifteen of which are the video, and every member watches it before touching a mold. A mold broken through carelessness is billed to the member who broke it, anywhere from about $40 to past $600. Normal wear is on us.