Working on white stock does tend to show up with crayon resist a bit more than working on colored stock, but... I like seeing how subtle the results can be. For instance... If I stamp an image on a yellow paper/cs, color it it with yellow, brown & do a final strong 'mask' of white, then swipe the piece with a blue ink, the BG becomes green. Once I buff the crayoned image it remains yellowish on a very different BG & I've used the base color & ink to make a brand new color mix. KWIM?