How to print a leather pattern at actual size

To print a leather pattern at actual size, print it at 100% scale. In the print dialog choose "Actual size" or set the scale to 100, and turn off anything called "Fit to page", "Shrink to fit" or "Fit to printable area". Then measure a known length on the printout, such as a 100 mm ruler, with a steel rule before you cut any leather.

That's the short version. Below is why patterns print at the wrong size, what a few percent does to a leather pattern, how to correct a printer that's off even at 100%, and how to print a pattern bigger than your paper.

Why patterns print at the wrong size

Fit to page. Most home printers can't print right to the edge of the sheet. A pattern PDF usually fills the whole page, so "Fit to page" shrinks it to the area the printer can reach. With a 5 mm border all round, an A4 sheet's printable area is 200 × 287 mm instead of 210 × 297 mm, and the page is printed at 95.2%.

The wrong paper. A4 is 210 × 297 mm; US Letter is 215.9 × 279.4 mm. Print an A4 pattern on Letter with fitting turned on and it shrinks to fit Letter's height: 94%. A Letter pattern fitted to A4 comes out at about 97%.

Pictures of patterns. A photo or screenshot has pixels, not millimetres. A photo viewer stretches it to fill the page, so it prints at whatever size happens to fit. Print from a PDF, or from a program that knows the pattern's real size.

The printer itself. Even at 100%, a printer can be a fraction of a percent out. The error is often different along the sheet, the way the paper feeds, from across it.

Hidden settings. Borderless printing enlarges the page slightly so it runs off the edges. Some printer drivers also have their own zoom or "fit" options, separate from the program's.

What a few percent does to a leather pattern

A 4.8% error (printing at 95.2%) sounds small. On a leather pattern it isn't:

• Stitching holes drift. A 3.85 mm hole spacing prints at 3.67 mm. After 20 stitches the printed holes are 3.7 mm away from where your iron puts them: nearly a whole stitch.
• Pockets stop fitting. A card pocket drawn 90 mm wide between the stitch lines prints 85.7 mm wide. A bank card is 85.60 mm wide, so there's no room left for the card to go in.
• Panels come out short. A bag panel 300 mm tall loses 14 mm, and its gusset no longer meets the top.

How to print at 100%

Every program words it differently, and the names change between versions. The idea is always the same: find the scale and make it 100, and switch off every kind of "fit".

Program	Choose	Turn off
Adobe Acrobat Reader	Page Sizing & Handling: Size, then Actual size	Fit, Shrink oversized pages
Chrome and Edge	More settings: Scale set to 100, or Actual size if it's offered	Any "Fit" option
Firefox	Scale: 100	Fit to page width
Preview on a Mac	Scale: 100%	Scale to Fit

Then check two more things:

1. The paper size. Choose the paper the pattern was made for, A4 or Letter, in the print dialog and in the printer's own settings.
2. The printer's preferences. Open Properties or Preferences for the printer and turn off borderless printing and any zoom or fit setting there.

Check the scale before you cut

Always measure before you cut leather. Use a steel rule, not a tape measure or a cloth tape, and measure in good light at eye level.

• Measure both directions. Check a 100 mm length across the sheet and another along it. A printer can be right one way and wrong the other.
• Measure something long. A 1 mm error is easy to see on 100 mm and easy to miss on 20 mm.
• No ruler on the page? Draw a rectangle the size of a bank card, 85.60 × 53.98 mm, and lay a real card on the printout. Any difference shows straight away.

The free printer scale test page has 100 mm and 4 inch rulers to measure. Print it once on each printer you use, and again whenever you change the paper or the printer's settings.

If it's still off at 100%: work out a correction

Some printers are slightly out even with every setting right. Measure the printed 100 mm ruler and divide what it should be by what it measures:

100 mm ÷ 99.4 mm = 1.006, so print at 100.6%

If it measures 100.6 mm instead, 100 ÷ 100.6 = 0.994, so print at 99.4%.

A print dialog's scale changes both directions at once. If your printer is out in only one direction, correct for the direction that matters most on the pattern, such as the long side of a belt. Some dialogs only take whole numbers, so 100.6% becomes 101%: measure again after the correction, because the rounding can leave you further out than before.

Printing a large pattern on A4 or Letter

A tote bag panel won't fit on one sheet, so it's printed in tiles and taped together. Worked example: a panel 350 × 400 mm, on A4 portrait with 5 mm margins (200 × 287 mm printable) and 10 mm of overlap between tiles. Two sheets across cover 390 mm and two sheets down cover 564 mm, so four sheets do it.

• Leave an overlap of about 10 mm with marks to line up, so you can match the sheets exactly.
• Assemble on a flat surface. Trim one edge of each overlap, line up the marks, and tape the back.
• Measure across the joins. Small errors at each join add up. Check the assembled pattern's full length with a steel rule or a long rule before you cut.

Adobe Acrobat Reader can tile a large PDF page itself: choose Poster, keep Tile scale at 100%, and set the overlap. A print or copy shop can also print the whole pattern on one large sheet. Ask for it at 100% with no scaling, and still measure the ruler.

Paper, card and templates

A paper printout is fine for a one-off. For a pattern you'll use again, glue the printout to card or template plastic with spray adhesive or a glue stick, then cut it out with a sharp knife against a steel rule. Paper moves a little with damp and dry air, so recheck an old template against a rule before a new batch.

How PatinaCAD does it

PatinaCAD prints leather patterns at actual size. It prints or exports a PDF at 1:1, tiled over as many A4 or Letter sheets as the pattern needs, with an overlap you choose and a 100 mm ruler on the first page.

• Calibration. Print the calibration page at actual size, measure its two 100 mm rulers with a steel rule and type in what they measure. From then on PatinaCAD corrects every print, across and along the sheet separately.
• Print areas. Press F7 to see the pages as frames on the drawing, and drag them so a page join doesn't fall across a pocket or a row of stitching holes.
• Holes you can cut. Stitching holes print as solid outlines by default, or as dots at their centres for marking.

The user guide's printing chapter covers every print option. For the stitching side of accuracy, read how to space stitching holes evenly.

Quick answers

Why is my pattern smaller even at 100%? Something else is still scaling it: the paper size, borderless printing or the printer's own settings. If all of those are right, the printer itself is slightly out, and a correction fixes it.

Should I print a pattern with "Fit to page" if it has a ruler on it? No. Print at 100%, then use the ruler to check.