YEAH !! note i will be replying to both comments on this one :3c
so basically here's the tutorial!, the transparency tool does work for gradients, patterns , among other stuff! in order to make the dots (polka dots!) from your previous question, this is also the way to do so! i made an image with pixelated polka dots pattern, and i paste it on top of the transparent color just like its made on the gradient tutorial :3 and then i paint the polka dot's colors so it matches with the shading! hope this helps and i hope its not too confusing !! KJHGHJ

also!! im not exactly sure since it depends on the person rlly... i never exported MS paint drawings on other programs so im not entirely sure about that :[ tho my drawings always tend to be less than 5000x5000 canvas!