Do laser printers change the nature of the paper?

A laser printer uses 2 hot rollers as the final stage of printing to fuse toner to the paper.

The fuser stage heats the paper and melts the toner before the copy is ejected into the tray. The fuser temperature can be as high as 350 F in some cases.

There are 7 stages to xerography first commercially available by Xerox Corporation printer in 1960. I found this an amazing process especially in High Speed devices that put out a page per second or more.

During the xerography process the paper takes part in several of the phases.

Most laser printers use a combination of heat and pressure during the Fixing/Fusing Stage. This is where it bonds the previously electrostatically charged toner particles to the paper.
Paper qualities also have a play in this. All copy paper is not made equal.

I recall the design of a Xerox Laser printer (XP2400) that I had engineering responsibility for. It used no pressure roller but only a heat fusion oven to melt the toner onto the paper. When it worked properly the quality was a raised embossed shiny beautiful print. If there was a problem in this stage, the paper could get brittle and in some cases actually catch on fire (Fahrenheit 451). Early models actually had a small fire extinguisher attached.

It looks like the answer to your basic initial question is no, the nature of the paper is not changed although at least some parts of the paper are heated in the process of manufacturing the print upon the page.

@kritiper It’s just that the paper that came out after the print felt different to before it went in.

@omtatsat – it got toasted at 350F. That ought to make it different.

Paper holds humidity which would be driven out by the heat, so there may be some perceptible difference that would probably dissipate as it cool and rehydrates.