I am doing leather craft,

I am doing leather craft, but I don’t know what is a good size(thickness) for leather for cutting and engraving? could you share your experience about leather cutting and engraving on K40?

<2mm thick is difficult to engrave (it wants to burn straight through it, even at lowest power). So for engraving, 2mm thickness at least. Cutting is difficult on 3-4mm thickness. So for cutting, it works best on <3mm.

So ideally, for cutting & engraving, somewhere around 2-2.5mm thickness is probably pretty good.