I use multiple printers and suddenly all of them seemed to develop a similar problem to yours at the same time.
Turned out it was my son's A/C cycling and pulling the power down on that circuit. On my fastest printer you can actually hear the printer slow in sync with the power drop. It shouldn't effect the scaling but it did.
My oldest printer doesn't do this at all, so it tells me that manufacturers are probably making the power supplies as cheap as they can.
I've now got a power stabilizer thing for big home theaters and the problem is gone.
You may also want to make sure there are no power saving or toner saving settings turned on, no telling how the power or toner is "saved"!
--- In Homebrew_PCBs@yahoogroups.com, "godzilera" <yah.5.peteben@...> wrote:
>
> Although I have been making successful single-sided PCBs for a while now, I just recently decided to try making a double sided board with SMD (.5mm TQFP) parts. So, I went out and bought a new inexpensive Samsung ML-2165 printer. The problem I am having is getting the scaling right. It's inconsistent and varies from print to print. Plain paper works pretty good, but the Pulsar paper comes out too short. I tried adjusting the scaling in the Kicad print dialog, but it seems to come out either too wide or too short. Very frustrating, and I have wasted four sheets of TTS paper so far.
> I have a couple of boxes of HP glossy photo paper, so I may try that.
>
> Any advice?
>
> Thanks,
>
> Pete
>