How to trim by hand using crop marks?

Question

I'm quite new to printing graphics. I understand why crop marks are used when printing, and on the face of it, they seem quite straight-forward to use. However, when I went to trim a document I have printed using the crop marks that were added (using Illustrator), I came across an issue that has me confused.

Take the example above. If I was to trim the top of the document, using the two horizontal crop marks, then I would also remove the two vertical crop marks indicating the left and right edges of the final document. As a result, when I go to trim say the left-hand side of the document, there is no crop mark to use as a guide at the top.

My question therefore is: how is a document trimmed using crop marks such that when a cut is made in one direction (eg. horizontally) the crop marks necessary for trimming the document in the other direction (eg. vertically) are not removed? Or is there something else I am missing?

Answer 1

I found this on YouTube: Removing Crop Marks.

I guess you are not meant to use them for cutting thing out with scissors but like she did. It's probably quicker to do it this way but I still do what JVS does.

The video shows that the proper way to cut an image with crop marks is to use a ruler and a cutting knife. You line the ruler up with the marks and then run your knife between them (not cutting the ends of the paper) you can then still see the other lines and you can do the same for the other corners.

Answer 2

Assuming this is for a single print out (or not many), use a straight edge (ideally metal rather than a plastic or wooden ruler) and cut with a scalpel knife, or similar, with the image area inside (so you don't accidentally stray into the image if your knife goes off course), on a trimming mat.

The guillotine doesn't allow for this method unless you change the offset distance in print options to just inside the image area (e.g. offset -.5mm) so there is something left of the trim marks.

Answer 3

Comming from engineering, I would descripe the problem like that:

in most cases, the main interesst is in the size of the cutted final product, and so you know before ...(A4, or 4" by 3" or alike), therefore the crop marks are overdeterming the pitcure(1)! Although they are usualy put on all edges, in prinzip you only need one corner for X and one some how oposite for Y. Cut one on X the other on Y and the remaining to size.

ready.

You never should need to "mesure" the final size out of crop marks, because they are here to allow somhow tollerance (eg. +/- half a pt, +0/-1 mm or so depending on quality)

(1) that means, if your printout is 1% larger than expected (high humidity...) you have to decide who is correct the marks or the requiered size. There is always something "not exact"