Partially painting a midsole: To strip or not to strip?

[stick]

I'm gonna be painting the midsole on a pair of Flyknit Lunar1s. I don't wanna paint the entire midsole, just the top grey layer. I wanna paint it white.

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What would be the best approach to doing this? Should I strip all of the paint on the entire midsole? Or should I just strip the grey paint? Or would I be able to get away with painting directly over it without stripping it? Anyone know the best way to attack this?

 

[fresh out dabox]

i think you might have to strip because if you paint over it, that layer of paint wouldn't look smooth

 

[Sneaker P]

I wanna remove paint from the midsole to show the the white underneath. Should I use acetone?