So I was working on the redraw of this pic for the past couple days, and this afternoon fucked myself by saving the file at a quarter of its initial resolution. Normally when this happens you feel a bit sick and make the choice of flattening and moving forward or starting over from scratch.

...But not this time! I refused.

My buddy got me on to using vector layers as the base for my lines, and this saved my ass because they can upscale losslessly by nature of being vectors (meaning I wouldn't have to redraw from scratch). The other saving grace was that I kept my highlights and shadows as flat colour values on seperate layers. Despite them being rasters and prone to pixelation when upscaled, being a uniform colour meant I could blur them slightly to smudge out the artifacting while still keeping the area they covered intact and the effect mostly on point. My flats were also on a seperate layer, and they do need to be redone due to the same artifacting that affected the highlights and shadows...but it's a very simple task (the clipstudio bucket fill tool is wizard tier).

Had to share because holy shit I hate when this happens and I am so excited to have a failsafe and solution in hand moving forward. BASED CLIPSTUDIO, will move to scraps in a bit.