I recently got a small compact KNAON thermal document printer and had a real problem trying to properly insert the single sheets of paper so that they would track properly through the printer. I finally decided to make a guide that slips on the end and helps align the paper, but can be easily removed to store it in your briefcase. There is some spring designed into the part, but I found that adding a thin layer of silicon sealer on the inside and letting it dry, added a little extra grip when you slide it on the printer. I use PETG almost exclusively now, but I am sure PLA would work as well.