I’ve been looking through the documentation, trying to find anything about how to actually make a tileset. The only page on it just tells you what it is, but not how to make one.
“What is a tileset? As its name says, it’s a set of tiles, just like the color palette which is a set of colors. Each tile has an index and can be re-used in different position in the canvas on each tilemap grid cell.”
This is entirely useless. You cannot make a tilemap without first making a tileset, and you’re given zero instructions on how to do so, nor is there any intuitive way to do so within Aseprite (or any way at all, as far as I could see).
EDIT: Apparently you can make a tileset by copy/pasting your tiles into a tilemap layer, but again, as far as I could tell, this wasn’t really explained, and it’s not obvious from the GUI when making a new tilemap layer because it’s presented like tilesets and tilemaps are two separate things.