Colored QR codes in PDF and EPS too — as print colors

Until now a colored code was colored only in SVG and PNG. The PDF and the EPS, the files that go to the print shop, stayed black. Now all four formats draw the same colors, whether they are in the URL or stored on the code.

How the colors get into the print file

• Black and every grey are written as grayscale. That prints on the black plate only, and the tone is exact on screen.
• Any other color is converted to CMYK in whole percent. The dark blue #1F4E79, for example, becomes C 74% · M 36% · Y 0% · K 53%. A colored code therefore sits on at most three printing plates.
• Background like the SVG: as soon as a color is chosen, an opaque fill sits behind the code and its quiet zone, white or the background color. With bg=transparent there is none.

curl "https://qr3.app/v1/codes/r7f3Kx/qr.pdf?fg=1F4E79&bg=F5F0E6" -o qr.pdf

Good to know

• No color management: the conversion is a simple formula without an ICC profile, and the file is not PDF/X. Saturated green, violet and blue print differently from the screen. If a brand color must match exactly, give the print shop its CMYK values.
• Small codes are best printed in black or grey.
• Title and logo: the PDF title stays black, the plate behind a logo white, and the logo itself an RGB image.
• Before a large print run, always do a test scan on the real material.

What you need to do

Nothing. Codes without colors return exactly the same bytes in all four formats as before; codes already in print are not affected. Colors are available on every plan, including Free.

All details are under Colors in print.