Engraving on cork,

Not sure if the laser engraving belongs on this page but here goes,
Did a design on cork for coasters and if you were ever in sports or the military, cork and heat tend to be pretty darn messy. What do you use o. The cork to keep it from smearing, tried clear lacquer but it caused the burned cork to run…
Any tips will be returned with a Merry Christmas…:blush: