I purchased this book online and upon reading it I discovered that one page contains two pink papers with the text of the book printed on top of them.

enter image description here

On the papers is also printed the text:

Ref:M100 202X

Might it be that this copy was unauthorized for sale?

  • Oddly enough, I've now discovered 2 other pages in this same section of the book with these stickers. After reading through the answers, I suspect that during printing and binding, this specific section of the book was printed at the end of the roll. How interesting!
    – Cory Klein
    Sep 29, 2021 at 17:30
  • Pages in books are mostly printed in sets of 8 or 16 or even 32, then folded, cut and bound (actual order can differ with the different tech they use.) It would have surprised me more if you had not found an other page with stickers.
    – Willeke
    Oct 12, 2021 at 20:33

2 Answers 2


It's something to do with the splicing in of new paper rolls during the printing process.

I'll confess that I don't fully understand how it all works, but am confident I've tracked down something very close to what you found.

illustration of a pair of white rectangular tags marked with the code Ref:M100 201 X

Splice rupture tabs

These tabs are die cut and/or perforated to break instantly after the splice has been made to release the new roll for unwinding. They are also used to hold down the outer spire during rotation to prevent air pockets being formed (which can burst the splice preparation during acceleration). The number and type of tabs are determined by splice speed, paper grade and pattern shape.

I don't quite follow how they would end up at the orientation shown in your image, but it is certain that they should not make it through to a product for sale, those pages should have been counted as wastage.

You can read more in the PDF I used as a source which might, or might not, help you to a fuller understanding!.

Edit: A further PDF seems to confirm that these are ‘Splice rupture tabs’ which are used to hold a roll of paper closed prior to it being spliced to the preceding roll. The tabs are rectangular and have adhesive on the underside at both ends but not the centre where there is a die cut line or perforation. The ungummed portion goes over the edge of the roll.

Double sided splicing tape is attached further back from the leading edge than the rupture tabs.

The splicing machinery, I think, picks up the new roll by pressing the double sided tape onto the roll that is finishing, and cutting that roll behind the join. The pick up applies tension to the paper on the new roll, rupturing the tabs and allowing the paper to feed into the press.

I can somehow understand this without being able to picture it, so I hope it makes sense to others!

Diagram showing correct and incorrect placement of rupture tabs on roll-text adjacent explains that tab has a line which indicates how to position the un-gummed portion in the middle of the tab over the edge of the roll

  • 7
    I've heard that people will sometimes buy rare printing mistakes for large amounts of money, so maybe keep this book just in case. Sep 28, 2021 at 14:25
  • 2
    The location looks wrong too, especially combined with the orientation. It's perhaps an error that they ended up there at all, so the page wasn't rejected by the normal process
    – Chris H
    Sep 28, 2021 at 15:00
  • 2
    I think what's confusing is that the splice is referring to splicing the roll to itself (page 20 of that pdf), not to other rolls. In other words, it's to keep the roll rolled up until it's ready to use. Once the tab is broken, part of it will be at the very end of the roll, and the other part will be one diameter length into the roll. My guess is that the width of the roll is the width of a page in the book.
    – anjama
    Sep 28, 2021 at 18:30
  • @anjama that would make sense (strange use of "splice" though)
    – Chris H
    Sep 29, 2021 at 8:11
  • 1
    That PDF definitely looks to me like it's describing splicing one roll to another roll. It sounds like the "splice rupture tab" keeps the roll rolled up before the splice occurs. Sep 29, 2021 at 13:20

I do not work with paper but with plastic and sometimes our rolls of material do have a 'splice' in the length somewhere.
I guess that also happens with paper.

If the roll is broken and repaired or for some other reason two shorter lengths are put together to get to a standard roll size, glueing together is needed and this is that 'splice' which then can end up anywhere on the printed page.
It should have been noticed and taken out of the pages to be used but if it is in the middle of a roll of paper, it is more likely to be missed than if it is at the start or end of the roll.

The numbers on the pink pieces of paper are likely meaningless unless you work in the paper factory, as they are likely to indicate the production number of one or both 'parts' of the put together roll.

As this is the result of a printing error, you will be justified in returning the book and requesting one which is not marked. But as you can read all the text of the book it might not matter to you.

  • It would be rare for a roll to be broken and spliced, but high-speed printing presses are designed so that when a roll is about to runs out, they can simultaneously cut the end of the old roll and splice it to the start of a new roll, all while the press is running at full speed.
    – supercat
    Oct 12, 2021 at 18:03

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