Paint refusing to be removed

[AshRC]

Does anyone know what kind of paint this might be, and how I can remove it? I stripped the entire body with oven cleaner, then tidied up the last bits with brake fluid. Everything has been cleaned off nicely … and this paint hasn’t even faded 

(apologies for the MS Paint quality obfuscation)

[Tamiyabigstuff]

Appears to be under the body.

Try a pan scouring pad or maybe abrasive paper ? 

[AshRC]

Was hoping to avoid sanding it off. I’ve never seen such resistant paint before.

[Aerobert]

Last year I've bought a used F-350 shell and tried to remove the paint like you said. It was nearly impossible. The best results was achieved with graffiti remover in several layers. I put it in a box with a lid for soaking and could brush it off partly with a dishwashing brush. To be honest I gave up in the end and bought a new shell.

Maybe graffiti remover from the hardware store will help you.