Question about layers between different tileset sheets

I’ve been mixing tileset sheets, just testing things out. I’ve noticed that when I create a top layer and put a sprite on a background it works…but when I take a sprite from another tileset sheet and put it on the same background it doesn’t layer, even though I’m putting it on a top layer over the lower background layer. I think the sprite was on a white background which I assumed would just be universally transparent when moving over.

Obviously I’m doing something wrong. What are the rules that govern whether something will layer correctly?

Generally if you want your tiles to layer on top of each other, you need to create multiple layers. In addition, your tile image should not be completely opaque. You can use either an alpha layer in your image to make it transparent or you can mark a particular color as the transparent color in the New Tileset dialog.

tile image should not be completely opaque. You can use either an alpha layer in your image to make it transparent or you can mark a particular color as the transparent color in the New Tileset dialog.

Is there a tutorial video that goes into more detail on this? I watched the ones in the documentation section but it doesn’t go into too much depth on this.