Friday, July 26, 2013
DIY thermal labels
So I tried a little experiment one night to see if I could make this thermal label tape myself. I have loads of rolls of thermal paper from some prototype work I was doing a few years ago which involved a thermal printer. So I took a about 1m of thermal paper and using a ruler and box-cutter cut it into (approx) 9mm wide strips. Next I opened the tape cartridge (it wasn't too difficult ... no tools needed... but be careful not to break it).
I used a bit of sticky tape to mate my new thermal tape to the spool. It's important to note which is the top surface of the thermal paper (btw: I have it the wrong way up in this photo!).
The first try wasn't very successful. The cheap thermal paper I used is quite thin and the capstan roller wasn't getting enough purchase on the tape to pull it out of the cartridge: 
By gently pulling the tape while printing I managed to get a clean print. But the other problem was the paper was facing the wrong way, so the print was a mirror image of what it should have been:
Then I remembered I had a roll of high quality (thicker/heavier) thermal paper. So I tried that, got the orientation right and finally got a good result.
Am I going to use this hack? Probably not. A few problems: First it's rather labor intensive cutting the strips and spooling it up. Second there is no sticky surface... so you'd need to glue this on to whatever you're labeling. Also regular thermal paper doesn't age well when exposed to the elements ... it's likely to fade in less than a year, especially if exposed to direct sun light. But I thought it was still interesting enough to write up on the blog.
 The capstan roller is squeezed against the paper when the printer lid is applied. A wedge on lid squeezes the roller against the paper. It's possible that additional pressure can be applied to the paper by widening that wedge (eg by adding a few layers of duct tape).