ohhh, seeing these Classic's of Old-School Mspaint.exe Tips is very nostalgic to me, somehow, i spent aaaaages doing edits of video game pixel art in this program using these lil' secret features
so!! lemme add another magic trick to this list:
after using the Select tool, you can press Ctrl +/- to resize the selected bit, and unlike in later iterations of paint, where the resizing is based on the dimensions of the whole canvas, mspaint resizes it by exactly twice or half the size!
this means perfectly square pixels each time you resize it bigger (if it gets too big for the canvas, simply cut and paste it back in, to automatically resize the canvas to fit),
and if you resize it real small with multiple Ctrl - inputs and then back up again you can get a funny pixelated mosaic look (see: image above)
oh yeah, now that im thinking about mspaint again, i wanna share a little 'trick' i learned back in those days too, it's not a secret feature or anything, just something that became a big part of my workflow back then, since there's no Layer's in this program or anything:
basically, once you're done with the lineart of a drawing, copy it into the clipboard (optionally: paste it into another mspaint window or just saving it as a separate file, as backup), then you can freely draw on top of the lineart when adding colors/shading/etc, and once you're done you can paste the lineart image back in, while setting the selection mode to transparent background, and presto: lineart's back 'on top' of the colors, like layered arts!
(and then you can use the single-color erase trick from the original post above to recolor the lineart too, for a softer look)
