Calculating Creep Compensation

Recently a forum member asked if there was a standard guide or measurement to use for calculating the amount of creep allowance or shingling to use in saddle-stitched booklets or signatures. 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.

I went searching online for an answer as well. Once I got past all the glossary definitions (which did result in my updating my own glossary with a few more "also known as" terms for creep and creep allowance) I found a few specific techniques and guidelines for calculating creep allowance. The Nies/Artcraft Companies FAQ suggests that creep allowance can be calculated in this way:

Formula for amount of "Shingling" or "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 center of the booklet. This works in most cases but using a folded, drilled, dummy of the actual job stock is best.

Nies/Artcraft goes on to further describe 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 center 4-pager inside, the drill holes will not line up and will show the exact amount of "Shingling" or "Creep" to expect on that particular paper stock.

For another manual method of determining the amount of creep allowance needed, try this method described by Cummings Printing in their PDF file Tech Note 01: Dealing with Creep:

Use a previously printed saddle bound magazine of the same stock and page count, open to the center 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.

More Creep-related Information

• This GUA Forums posting discusses dealing with creep when text/images span the gutter.
  
  
• Not familiar with the term "shingling" as used with creep? Seems it has another meaning as well - beyond shingling a roof. Scroll to section 0007 and 0008 to learn about shingling as a patented method of dealing with some inkjet printer errors.
  
  
• Found while searching for creep/shingling information, this June 2003 edition of PrinTips, a PDF newsletter from MacMillan Graphics, Ltd. has some nice tips on making sure your document is ready for printing and binding. It describes and illustrates brochure panel sizes and has a tutorial on making a folded dummy to help with calculating creep adjustments.

^{Graphic © J. Bear}