I was a grad student at the time, but I was fascinated by this demo, and later purchased the pot to commemorate the insight it gave me: that the tension between the mechanical qualities the wheel imparts and the squooshy organic qualities of clay itself are what inspire me. I had always done a lot of stretching and alteration. After seeing this demo, I made myself some stamps out of clay. I still often use stamps. I have approximately one billion of them, if you count the rollers. Outside of rollers, they fall into three categories: flatties, innies, and outies.
Most of my stamps are flatties. They are the easiest to make, and sometimes when I want to be in the studio but can't think of anything I want to make, I might make a few flattie stamps. I start with a little coil with one flat end, let it dry a bit, and then carve or impress the design into it. Here's a flattie stamp, right here, with the impression that it makes:
Flatties are technically a subset of innies, I suppose, in that they compress the pot wall inward; but the impression itself is flat. True innies are concave, the center of the impression deeper than the edges, so they read as more organic. Outies, naturally, cause the clay wall the curve outward. It is necessary to push outward on the wall with a fingertip while stamping, to make the clay fill the stamp. Here are an outie and an innie stamp (respectively, from the left)and the impressions that they leave: