I have a laser printer, and I wish to print onto plastic sheets for creating boxes to hold playing cards. How would one go about the printing process, or is it even possible? What plastic should I use?
Generally what you would put through a laser printer would be called Transparency Film. Something like this: http://www.staples.com/office/supplies/StaplesProductDisplay?storeId=10001&catalogIdentifier=2&partNumber=829903&langid=-1&cid=PS:GooglePLAs:829903&ci_src=17588969&ci_sku=829903&KPID=829903
But this is thin stuff. I'm not sure it would be sturdy enough for your application.
You could give it a go though if a laser printer is all you have. Maybe print on the transparency film, but frame your boxes with sturdier plastics.
I am afraid that you need to consider not just a plastic but a laser printer, because during printing process heating is used and you have a chance to destroy your device.
You can check for specialized equipment at Plastic Printers. I am sure they also have clean plastic cards ready for print.