PUR Binding vs Perfect Binding – what’s the difference?

October 24, 2011

in Print work

When we produced our Type Can Speak book earlier in the year (click here to order your copy), we used a range of materials including a single acetate sheet.  PUR binding was the only real binding option available to us.  So what are the differences between PUR and perfect binding?

Fundamentally, the largest difference is between the types of adhesive used in the binding process.  Perfect binding uses ethylene vinyl acetate (EVA) adhesives whereas PUR uses polyurethane reactive (PUR) adhesives.  “So what?” I hear you say….

Well, the PUR adhesive offers superior adhesion over EVA and also the ability for the bound book to lay flat without compromising the binding strength.  The polar nature of polyurethane molecule allows it to adhere to UV-cured coatings, films, as well as to traditional uncoated and clay-coated papers.

Due to PUR using smaller amounts of adhesive over perfect binding it also means that you can achieve a square spine on even the thinnest of books.  PUR glue is more durable and flexible than EVA glue and, once the glue has set, it is almost impossible to tear a page out of a PUR-bound book.

EVA hot melt glues still have their place in book-binding, especially when it comes to binding thread-sewn books, as the thicker glue allows for greater penetration into the spine area of the folded sections.

For those of you that have not had the experience of seeing a perfect or PUR binding machine in action please do contact us – we very often include binding factory tours as part of our ‘mini print-inductions’ for designers and account execs.  In the meantime this video allows a taster from the comfort of your desk…

A perfect-binding line running at eight thousand copies per hour.  If you think it looks a little ‘Heath Robinson’, the reason you have long conveyor belts running between the binding area and three-knife trimmer is to give the adhesive time to ‘go off’.

{ 11 comments… read them below or add one }

Perfect Bound Books November 7, 2011 at 4:19 pm

I was under the impression that perfect binding requires around a 64 page document/magazine for the binding to be effective. Does PUR binding allow you to bind smaller pagination documents?

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Martyn Dolbear November 7, 2011 at 4:29 pm

Thank you for your comment Mark. I’m guessing that you would know better than us but in our experience it is not the number of pages but the overall thickness of the spine that makes the binding effective; be it Perfect Bound or PUR. In the days before PUR was available, we have successfully perfect bound 32pp’s of text. We recently produced a PUR bound job that only had a spine depth of 3mm and it held perfectly. The job was originally spec’d as 24pp text on 150gsm, we increased the text material to 200gsm to ensure an adequate spine thickness.

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Abigail Green October 31, 2012 at 8:12 am

Thank you very much for this explanation on the difference between PUR- and Perfect binding.

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Martyn Dolbear November 5, 2012 at 9:09 am

Our pleasure Abigail – I’m pleased you found it useful.

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John Hanton April 27, 2013 at 9:52 pm

I wanted to use PUR binding on a 432 page book using 30 gsm uncoated bible paper and the printer who has the PUR binding machine is advising against it, saying the pages will tear easily.
Other printers say there is no demand for PUR with thin paper so maybe there is some truth to the tearing assumption, but why wouldn’t the same pages tear from a perfect bound book?
The other issue I have is that it would seem over time, that the cover on the spine would give out, or at least look really bad after being bent over so far with repeated opening of the book.
Thanks for the info so far on this issue, it is very helpful.

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Martyn Dolbear May 1, 2013 at 7:48 am

Hi John – many thanks for your comment and query. Based upon the information provided, I have to agree with your printer in that your spec is beyond the capabilities of PUR binding. It doesn’t matter how strong the spine adhesive is, a 30gsm page will not have the strength to hold the weight of the book. Obvious questions would be:
1) How is the publication being used? Does it sit on a shelf and is just referred to on an occasional basis or is it used regularly?
2) What is the run length? Are we talking 10′s of thousands or just a minimum quantity?
3) What is the reasoning for choosing 30gsm bible paper? Is it to kep the overall spine width low or are there other reasons?

The cover will indeed dog-ear and wear with use and at the very least you need to matt laminate and make the cover weight as high as possible.

My recommendation, in the absence of a fuller undersatnding, would be to thread sew the text sections with a drawn on cover and endpapers.

Good luck John.

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elvira d'adam June 6, 2013 at 9:36 pm

Martyn, I have found your article on PUR binding extremely informative. I have had a book on the family history published (perfect binding) and they began to fall apart within a week and now they are suggesting that it be PUR bound. My book is of 440 pages – 128gsm silk with a soft cover which has been laminated. To be honest I am feeling uneasy about this process and would like your comment. What would you suggest keeping in mind that these books for for our family to be kept as historical information. Your reply much appreciated. Kind regards Elvira.

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Martyn Dolbear June 7, 2013 at 9:47 am

Many thanks for your feedback Elvira, I’m pleased you found the post of use.

Firstly, I’m sorry to hear that your first delivery of your book was not fit-for-purpose. I’m sure you put a lot of effort and energy into publishing the book and after the initial excitement of receiving the first copies you must have felt very disappointed to find them falling apart in your hands.

With regard to your query, I would like to give my thoughts and suggestions as below.

Some perfect-binders are not actually robust enough to effectively bind a book of 400pp (220lvs?). To use an analogy – you cant really say a diesel engine car is better than a petrol engine car if you’re comparing a diesel Kia with a petrol Mercedes. There are a huge range of machines used for binding – some are almost ‘desk-top’ in their format whereas others are the size of a sports field. Having said that – I think the format of your book would push the effectiveness of any perfect-bound job and PUR-binding would always give a stronger result.

If you wanted an absolute fail-safe, no risk binding method then I would recommend thread-sewn sections with a drawn on cover, however this may not be viable and is subject to how your book was printed – digitally, sheet-fed, reel-fed etc. It also has much higher cost implications than PUR or perfect-binding.

From the spec you provided, I would guess that you’d chosen a 128gsm silk text paper as there is full colour imagery throughout the book? If you are self-publishing a full colour book with 440 printed pages then it indicates that you are digitally printing. If this is the case, then may I suggest your print provider reprints a small test run, finished as PUR-bound and then you test the strength and robustness; before committing to a full reprint. Do remember though that PUR adhesives need 24 hours to ‘go off’ to achieve maximum strength so the books really should not be handled for at least one full day after being bound.

Please do let me know how it goes Elvira and I wish you all the best.

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Siobhan August 14, 2013 at 4:32 pm

Hi Martyn, great article. I’d love to get your opinion on the following book spec and if perfect binding will be ok for a book of its size and weight.
Option 1:
B5 size
256pp+ Cover
224pp in black on 90gsm
32pp in full colour on 130gsm
Cover on 350gsm laminated
Folded and perfect bound

Option 2:
As above but case bound

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Gavin Hay August 15, 2013 at 11:23 am

Hi Siobhan, many thanks for your comment on the article and query. Due to the mixture of text stocks and the fairly high pagination we would recommend PUR binding over perfect binding. Obviously thread sewing and case binding would be the strongest and possibly best option but this might be cost prohibitive. If you are able to supply quantities we would be more than happy to provide you with some production costs for this project.

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Harry Hanks September 14, 2013 at 3:02 pm

Thanks for the education … Is it true that the PUR adhesive is twice as expensive and …. must it dry overnight ? In many cases the van is waiting …. does it mean that the van can’t wait with PUR ?

Reply

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