Let’s take a look at the main binding methods used in commercial printing – How they differ and what we need to know about them to get the best results…
With printing complete the job needs to be bound – that’s the collating, folding and trimming of the printed sheets. There are a number of binding methods available but to decide which one is suitable for your commercial print job it’s important to consider the following:
- the size of the document
- the intended use and lifespan
- the type of content
- the client’s budget
It’s equally important to discuss binding options with your commercial printer as timing and pricing can affect your final decision.
Saddle stitching is used when a soft cover document is held together by staples. For example, an issue of GSM magazine.
Saddle Stitching is done by collating the folded signatures (along with the cover) and then stapling these together along the folded spine. The document is then trimmed on the outside edges to size. A signature is the name for a printed sheet of untrimmed imposed pages— usually 4, 8 or 16 pages per signature.
Saddle Stitching is an economical way of binding as it’s both fast and efficient.
Things to consider when saddle stitching:
- Number of Pages – The size of the document is limited to the number of pages that can be saddle stitched. This is because of the thickness of the collated stock as the staple has to be able to penetrate through the paper. Usually, the limit is about 64-68 pages using a paper stock of 150gsm. Using a lighter weight (for example, 128gsm) you might be able to bind up to 72-80 pages but check with your printer first. Also, keep in mind that if you go with a lighter paper stock, you run the risk of showthrough.
- Page creep – the combined thickness of the folded signatures at the binding edge pushes the pages outwards. This is called page creep where pages at the centre of the document are pushed slightly out of alignment with pages nearer the front or back cover. Page Creep creates a potential problem with design elements that appear on every page (eg. page numbering or footers being cut off). Shingling is the process of offsetting each page slightly to compensate for this page creep. Shingling is usually done by the print house as part of the imposition process—but it pays to check that they will do this.
Burst and perfect are two binding methods used for a soft cover document which result in a squared-off spine (eg. glossy magazines and soft cover books). Sometimes, the name burst or perfect is used interchangeably but they are not the same thing. The key difference between the two is in how the spine is prepared for binding.
In burst binding, the folded signatures are grouped together and notched with a special machine along the folded spine. This notching creates a rough edge for the adhesive to grip to as the signatures are glued into the wrap around cover. Once the binding glue has set, the document is then trimmed on the outside edges.
In perfect binding the folded signatures are pre-trimmed along the binding edge prior to gluing. This means the document is bound as individual pages, instead of as groups of pages like burst binding.
Things to consider:
- Perfect Binding is less involved than burst binding so is usually more cost effective.
- Burst binding is more durable – think long-life or high-read documents such as magazines or non-fiction soft cover books whereas short-life or low-read documents such as paperback novels are perfect bound.
PUR Binding is an alternative form of perfect binding that uses special Polyurethane Reactive glue. It has far superior bind strength and better lay-flat flexibility, as well as resistance to temperature extremes. This method is also compatible with a wider range of paper stocks.
Things to consider when Burst/Perfect/PUR binding:
Number of Pages –
No staples means significantly more pages can be bound together. Burst or perfect bound documents can go up to (and in some cases exceed) 300 pages.
To achieve a cleaner, more professional look you may opt to burst or perfect bind a document rather than saddle-stitch. However, a minimum number of pages is required for burst or perfect binding before the spine becomes too narrow to provide adequate strength (usually, not less than 32 pages). Check with your printer, as different paper stocks and adhesives will result in different minimum page requirements.
Gutter loss –
Due to the rigidity of the binding method, burst and perfect bound documents are unable to open completely flat to the same extent that saddle stitched or PUR-bound documents can. This means the centre of your spreads will be lost into the gutter— hence ‘gutter loss’ (approx. 3-5mm lost on the binding edge of all internal pages). The simplest way to avoid this in your design work is not to run anything critical across the gutter. However, this is not always practical—particularly if you plan to run large images across a spread. To compensate for this, it is advisable to manually offset any images that run across the gutter by 3-5mm in both directions. This means you will need to split the image in two halves, one half on the left page, the other half on the right page—and then move these away from the centre line by 3-5mm.
Time and cost factors –
Burst and perfect binding are more time-consuming and thus more expensive to produce.
Hard Back Books and Case Binding
Most hardback books are case bound. This method starts with the collation of the printed, folded signatures (similar to burst binding), which are then sewn together before being glued to the end-papers and trimmed. The end papers are then glued to the hard cover. This process requires manual labour time, hence the increased cost between softcover and hardback books. Hardback case binding is always undertaken by a specialist bookbinder.
So, binding decision made – not quite!
Ideally, we make our decisions based on the requirements of the job. But let’s be realistic – client budgets and deadlines rule our lives! Production time not only increases the cost but can also push deadlines out. Sending out to a specialist bindery, rather than completing in-house also adds to the budget and deadline. We recommend speaking to your printer early in the process. Together, you can decide on the best binding option for your print job.