Bob- I think the reason the paper is curling is due to the fact the image is bonded to the paper with heat in a laser printer. Paper coming out of any thermal printer tends to curl. If you are old enough to remember the first copier on the market back in the 60's the "Thermofax" made by 3M. It was horrendous for curling the paper. I think some other brands that don't curl as much have another roller after the heat setter roller that reverse bends the paper so they come out flat. We used to take the Themofax pages and pull them down across the edge of a table or sharp edge with the back towards the edge to take the curl out. They would usually curl again in a day or so, particularly if the humidity was high. The side of the paper with the print on it cannot expand as much as the blank side. Suggest you Google "How does a laser printer work". You will find numerous explanations of what happens inside the machine. HTH John Dinges Visit our website regularly for FAQs, articles, how-to's, tech tips and much more http://freepctech.com