A printing term that confuses
Creep is where the bulk of the paper in a saddle stitched booklet causes the inner pages to extend or creep further out than the outer pages when folded. The illustration shows an exaggerated view of how the inner pages of a saddle stitched booklet creep out and extend beyond the edge of the outer pages when folded.
The amount of creep allowance needed depends on the size of the margins, number of pages, and the thickness of the paper. A booklet with few pages and wide margins might not need creep allowance because the difference after trimming is not noticeable. With more pages, smaller margins, or bulkier paper the creep becomes more noticeable and can result in loss of text if there is no adjustment made. If creep is noticeable, copy can be repositioned toward the centre of the spread for those pages in the middle of the booklet. When trimmed, all pages will have the same outer margins and no text or images are lost. Some page layout software can automatically calculate creep allowance and adjust layouts for creep — moving the page elements of affected spreads in small increments.
Calculating Creep Compensation
Printing companies will have charts or some type of software that uses the number of pages and thickness of the paper to calculate the amount that the layout needs to be moved toward the gutter to keep the margins even after trimming.
Formula for amount of creep:
Total pages in book, divided by 4 (for each 4 pager), times paper thickness. Take that number, and divide it by the number of flat sheets in your book. This number will be quite small, but will represent the amount that you should adjust each page’s outside margin, as you get closer to the centre of the booklet. This works in most cases but using a folded, drilled, dummy of the actual job stock is best.
How to use a folded dummy that has been drilled (holes) to figure out how much creep allowance to use. This is also suggested by other sources as the best way to make sure that the correct allowances are used. First, make a dummy using the actual stock that you’ll print on, fold and drill it. By removing the 1st 4-pager and placing the centre 4-pager inside, the drill holes will not line up and will show the exact amount of creep to expect on that particular paper stock.
Use a previously printed saddle bound magazine of the same stock and page count, open to the centre spread and lay the magazine flat, now measure the distance from the trimmed edge of the innermost page to the trimmed edge of the cover, this is the required adjustment needed.
These are some of the examples to compensate creep. If you are sending a document to a commercial printer, they will impose it and adjust for creep. If you are printing from an office printer, you can allow for creep in InDesign. However, if you are using another application to print a booklet, you will need to allow for creep manually.
Taking expert advice on creep from your commercial print
Processing formulas for dealing with print creep may seem a daunting prospect. Which is why it makes sense to speak to your professional print company about this aspect of the print reprographics.
At PrintHouse we have over 30 years experience laying out booklets to accommodate for creep and we be delighted to assist with your next booklet all magazine printing project.
Give us a call on 020 8963 0123 or use the contact form below.