What is bleed, and how do I achieve it?

Question

I am going to print business cards that I've created using LaTeX, and when I contacted the print company and asked what they needed for the print, they answered that they needed a "pdf with the correct page size, including a 5 mm bleed."

I've read up on wikipedia and understood that when you print something, you usually print it on paper that is too large, and then cut away the extra to fit the page size. This "extra" is, if I understand correctly, called bleed. Is my understanding accurate?

I intend the finished business cards to be 85x50 mm, printed on white paper with a faint watermark. I've fixed the paper size with the geometry package and "underlayed" the watermark using the eso-pic package, so that's down allright. The watermark image is large enough to span almost the entire card, but it is white (transparent) all the way around the edges, so it doesn't actually touch the paper edge.

How do I achieve in LaTeX what the printers ask for? Do I simply adjust the paper size to 10 mm extra in each direction, or should I do something more advanced than that? If it's more advanced, how do I do it?

Answer 1

As you said, printers print content on paper larger than the final trim size, and then they cut it to the right size.

When they print content that touch the edge of the paper (typically, if there is a background color), then the content must be larger than the indented paper size in order to ensure that you won't get white borders when the content is cut.

The following image (from the lulu.com online printer) demonstrates what bleed is:

In this example, a 0.25" bleed is used. The trim size is 6x9", so the document has to be provided at a size of 6.25"x9.25".

In order to achieve this with LaTeX, you can use the geometry package, or you can switch to Koma-Script classes (such as scrartcl, which is a drop-in replacement for article) and use \areaset as described in this answer. The crop package can also be used to add crop marks for trimming.