FoldPin

Sewing-hole guides for folded signatures.

Coming soon to the App Store

In development. Not yet on the App Store.

Set the hole positions for a folded signature, keep the guide, and export a printable strip at actual size. For binders who already know the spacing they want.

FoldPin is a geometry tool, not a sewing tutorial. You choose the positions; it holds them, shows them, and prints them.

Three ways to set the positions

Illustration drawn on this page. It is not a screenshot of the app and it is not printed at actual size. The positions are the worked example: a 210 mm guide with 15 mm head and tail offsets and seven equally spaced holes, giving 15, 45, 75, 105, 135, 165 and 195 mm from the head.

Millimetres or inches

Work in either unit. Switching between them changes the numbers you read, not the guide: the dimensions stay the same. Inches accept ordinary fractions such as 1/2 and 4 1/2, and decimals use your keyboard's decimal separator.

Guide lengths run from 30 to 600 mm, with 2 to 60 holes, every hole at least 2 mm from each end and at least 2 mm from its neighbour. Those are software and mark-legibility limits, not advice about what a binding needs.

A library of saved guides

The printed strip

Printing at actual size

Print at 100% or Actual Size, with Fit to Page or Scale to Fit turned off. Then measure the 50 mm check line on the printed sheet before you use the guide. If it does not measure 50 mm, the print was scaled and the hole spacing is wrong.

FoldPin draws the PDF at actual scale. It does not control your printer, your print dialog or your paper, and the on-screen diagram is a preview rather than a ruler.

What FoldPin leaves to you

It does not recommend a sewing structure, teach a stitch, or say anything about how strong a binding will be. It does not import a book PDF, impose pages, or calculate boards and cases. You decide the positions for the method you are using.

Price

2.99 US dollars

One purchase. Every guide, every layout and every PDF export is included.

That is the United States price. Prices in other regions come from Apple's regional price tiers and vary. No subscription, no in-app purchases, no advertising.

Your data

Your guides are stored on your device. The app does not upload them to us, has no analytics and needs no account. Device backups may include them, and a PDF you export goes wherever you choose to send it. The privacy page has the detail.

Requirements

iPhone, iOS 17 or later. Portrait and landscape. Dynamic Type, including the larger accessibility sizes.