Right now, paintings can be created for free. The painting in the output slot disappears when taken, but appears again when closing and re-opening the GUI.

Instead I think there should be a slot that takes a stack of paper. Each painting taken would consume 4 paper. Taking a painting would no longer cause the painting in the output slot to disappear.

4 paper is the cost of making a new canvas, which presumably is what paintings are copied onto. Since canvases can't stack this would require less inventory juggling.

I believe I did all of my testing in creative mode. A copy machine sounds like a good solution.

Canvases should be removed after crafting if you're in survival. For a while, in creative mode, canvases are saved so you're able to edit your work.

For copies, I think there'll be a special copying machine or something like that in the future.

Thanks for suggestion!