Printed booklet changes margins on every second page

Question

I have encountered a very strange problem. I am printing booklets (abt. 80 pages) where one page is in A5 format, the arranged booklet-pages by InDesign are all in A4 and I have to arrange these booklets on A3 to print two booklets at one time. I'll attack a screenshot of the final arrangement.

When printing on our office printer, every second page has a different margin, it seems like the printer changes something when turning the page, as it is always one side of the paper, the only two consecutive pages with identical margins are the ones in the middle.

I can't find out what the problem is, all the margins are correct in the arranged InDesign document so it has to be the printer.

I asked in a copy shop, they also claim it was the printer. Other colleagues though have worked with that printer before, and their booklets are completely fine. I know that the printer has its usual printer-problems including paper jamming when printing A3.

Extra question for the comments: If I cannot fix the problem in time, would it look better to abolish the baseline grid at all. Is it better that everything isn't quite right than one detail not being quite right.

Answer 1

End use home/office printers are not designed to pull paper in the exact same position every time. They do not have any registration.

Paper will shift, or move, as it's fed through the printer. If you are printing duplex pages the shifting can occur when the same piece of paper is fed through a second time. It's actually fairly lucky that you get a consistent mis-registration. It will often change in minute ways with each and every print job. The smaller these shifts, the better the printer. However, they will always occur.

Thinking a bit more about this, the shift you are seeing could simply be due to the printer's gripper edge. The margin on the edge that is gripped to pull the paper through the printer is often slightly larger than any other margin. If your printer flips the page, and pulls opposite ends through to create the duplexing, that would account for why every other page (or the backside of every page) has a slightly larger top margin.

Your colleagues may not be as aware of margin shifts as you are but it's doubtful they got any better results. Be aware that noticing this kind of thing is not something the general public sees. It's one of those aspects the designer/artists sees because they are aware of these sorts of things. The public has no clue and unless there's some wildly glaring error, the public won't notice.

The only way to ensure all pages register the same on each folio is to use a commercial press, not an end use printer or digital copier.