Laser printer 'bends' paper

Solution 1:

Yes, it's a common problem. Especially in environments where the humidity is high. Humid paper = more curl.

The design and specification of the printer also matters. Printers whose fuser unit is designed to run hot will cause more curl. Also, if the printer is designed such that paper travels around tight rollers in a U-shape (especially at the point where the paper goes through the hot fuser) then you get more curl.

Small printers are more prone, but then my Brother HL-2250DN seems pretty good. However, I keep my room's humidity under control.

To sum up, this is a common issue, it's not (normally) a sign of a defective printer, and some printers are better than others in this respect. You can minimize the issue for yourself by getting your room's humidity under control or storing your paper supply in a dry place until you need to use it. If you have a hot water cupboard that's not a bad place to keep your paper.

More reading/tips if you're interested: http://word.tips.net/T003507_Reducing_the_Curl_in_Printed_Documents.html

The above article gives a few extra tips, like flipping the paper over (because paper tends to bend more in one direction than the other) and finding which way around produces less curl. You could try other kinds of paper, but do make sure such paper is laser-compatible.