Not sure if this has been posted before (couldn't find in a quick search).
This guy and some others are making decals using Laserjet & clear packing tape. I have tested it myself and the result was great just using an MS Word font, home laser printer and Norton Bear tape. Actually stunned how crisp and solid the print comes off the paper and the clarity of the tape. I applied it on my ES3 poly finished headstock, and it slid about like a waterslide for positioning.
Looks great at the moment but long term you would want to put a coat of poly over the top. And I'd want to test how the tape and poly interact before that.