Recently two of my friends got married, and I made personalised bottle caps for the placeholders/party favours. The bottles, which were to be filled with lollies used to contain medication and had to have their original rubber lids replaced because there was a possibility of needle contamination. I made the hundred new lids out of cork and rimu veneer MDF, and not only did they work well, but they even made a cork popping sound on opening! Cork is a horrible horrible material to laser cut because it charrs very badly and doesn't give a good edge. Ideally it's stamped out or turned, but neither of those fabrication methods were an option.