Painted Kitchen Windowsill problems

[rob4beer]

Hi All,

Ive painted the window sill in our kitchen with silk paint, its an ok finish after a couple of coats, if anything is left on it even slightly damp it leaves a mark and sometimes tiny bubbles where its been sat.

Is there anything I can do to counteract this? any better paint to use or am I screwed whatever i try lol

thanks in advance for the help