What are crop marks and why would you want to print them?

Crop marks, also known as trim marks, are lines printed in the corners of your publication's sheet or sheets of paper to show the printer where to trim the paper. They are used by commercial printers for creating bleeds where an image or color on the page needs to extend all the way to the edge of the paper. Printers generally can't actually print to the very edge of the paper, so instead they print on a larger sheet of paper and then trim it down to the correct size. Crop marks are used to define where to trim. So, to print crop marks, you must print on a paper size that is larger than the page size you have set for your publication.

Photoshop How-To: Adding Bleeds and Crop Marks

What is bleed, crop marks and the safe area? – Peterkin Help Centre

Files - THE PRINT SHOP'S SHOWCASE

What are crop marks and bleed?

Add and print crop marks in Publisher - Microsoft Support

Microsoft 365 Blog Latest Product Updates and Insights

Understanding Bleed and Crop Marks for Printing: A Comprehensive Guide - Coast Print

Why do printers ask for crop marks and bleed?

A Printer's guide to crop marks and registration marks

Need to Know Printing Terms Bleed, Gutter, and Crop Marks!

Using trimming settings (Crop marks)