Determining Spine Width

[prepressdork]

Hi all,

I realize this might seem like a dumb question but on a perfect bound project, how do you determine spine width? By this I mean physically? Electronically? If electronically, would you be willing to share exactly how you do it?

Thanks,
pd

 

[mwc]

have used an app called "spine calculator 1.0" by Big, Fat, Stinking Software, although it is old (does not work beyond mac OS 10.6) I don't think there was ever another version...If you search the interwebs for "spine width calculator" there are several online resources available.

Like this one : http://www.bookmobile.com/art-book-...-and-book-weight-before-your-book-is-printed/

 

[prepressdork]

Hi mwc,

I found it and it indeed does not work beyond 10.6 (it's a PowerPC app). I did test it. On a 122 page (not including cover) 70# gloss text (custom weight entered), I get .2013. The spine for the project was measured at .25" using the actual stock.

Thanks,
pd

 

[kyle]

We've always multiplied the text caliper by the number of 2 page leaves, added 1/32 inch, then rounded to the nearest 1/32 inch. If it were up to me, I'd probably round to the nearest .01 inch, but I don't think we've ever had to reprint anything due to inaccuracy (except when someone uses the wrong caliper or page count).

 

[Alith7]

I usually just grab a stack of the original stock, measure it, add the caliper x2 for the cover stock, plus 1/32" to allow for corner wrap. It usually works pretty good. Otherwise, If you can't get your hands on the stock, multiply the caliper of the paper x # of sheets then add the caliper x2 of the cover stock + 1/32". If I'm doing it off the caliper I usually add about 10% or 1/32" extra (whichever is smaller) to allow for "air" in the clamping.

Example:

70# gloss text 122 page (assuming 61 sheets)
.003 * 61 = .183 + 10% = .2013

assuming 100# Gloss Cover for the cover
.0091 * 2 = .0182 + .03125 = .04945

add the two together
.2013 + .04945 = .2575

So, technically, both you and the online are right.
Just make sure when you are measuring a full stack, to tighten your caliper as tight as it will go, then back off a hair. the binder never gets ALL the air out when clamping.

 

[afilsonCSA]

The easy answer is total number of pages divided by 2, multiplied by the (Caliper) thickness of the paper, but that assumes softcover perfect binding. If case perfect binding there is a roundness factor to consider, and that depends on where the case binding is occurring (which region of the world) as different areas of the world have different amounts of "roundness" for case binding, plus the crash adds some distance. There is also layflat perfect binding, which of course is a different calculation altogether (see attached). hope this helps.

 

[afilsonCSA]

oops, I deleted one too many pages. Here it is with the case binding info