July 1, 2011

"There Will Be Bleed"

Adapted from a presentation I gave at Foothill College's Letterpress class on June 25, 2011. Some information may only apply to specific equipment at Foothill.

Bleed is a printing term that refers to printing that goes beyond the edge of the paper sheet. This is accomplished by printing on a larger piece of paper than the finished size, and then trimming off the excess to ensure that the unprinted edges don't occur in the final document.

By now, I've printed a few designs with bleeds, and want to share some techniques I learned through trial and error that will help save time and work, and increase the likelihood that your final product will turn out well.

But first, let's examine some of the problems that can happen when you print a design with a bleed. In these examples, I'm using a set of 2-color "business" cards, but these issues could apply to any design.

You are a master printer, and whatever you envision, you can faithfully reproduce on the press. Your finished prints look like this:

Ideal prints

A) Parallel edges: the sides of the paper are parallel to the edges of the design, so it's easy to position your finished prints in the paper cutter.
B) Perfect registration: all colors are exactly where you want them, in relationship to each other and the paper. Your crop marks overlap completely.
C) Consistent registration: all the sheets are printed in the exact same location (i.e. the paper was fed into the press the same exact way each time).

Then, when you go to trim, you can simply
  • stack all your prints (because of the consistent registration), 
  • position them in the paper cutter (thanks to the parallel edges, you don't need to set up unusual angled cuts), and 
  • make the following cuts (following your perfectly registered crop marks), ordering them to avoid unnecessary adjustments of the paper cutter:

Ideal trimming order

1) Cut one side
2 & 3) Cut a perpendicular side(s)
4) Cut 3.5”
5 & 6) Cut 2”

Your first 2 cuts are perpendicular to each other, so you can get a square edge to start with. Continue making cuts in an order that ensures you will not cut off all your crop marks at once, or have to adjust the paper cutter more than you have to. In general, cut perpendicular to the last cut you made to avoid cutting off all your crop marks at once.

For the rest of us, things don't always turn out so perfectly. If your paper wasn't perfectly square or had lovely but troublesome deckles, if you don't have a press with an automated paper-feeding mechanism, or are in a rush (time is the greatest luxury), your prints might look more like this:

Realistic prints

A) Nonparallel edges: edges of design are not parallel with edge of paper.
B) Poor registration: If printing multiple colors, colors are not registered; crop marks of one color may fall within design area of another color.
C) Inconsistent registration: printed area falls slightly differently on each piece of paper.

Then, when you go to trim...

Don't give up; there is hope

It doesn't have to be like this. There are several things you can do before and after printing to prevent this. The following techniques can help:
  • Reduce number of cuts (and number of times you have to re-configure the paper cutter),
  • Use less paper and photopolymer,
  • Allow for less than perfect registration (thus salvaging mis-registered prints).

After completing your design: How to Set Up For Printing Bleeds
1. Offset your crop marks. This decreases the chances of crop marks appearing in the design area.

If printing multiple colors, decide which color is the most important to trim to; offset crop marks of all other colors even more than this one. For example, I've decided that the pink is most important to have properly registered on the paper, so I have offset the black much more than the pink. This is especially helpful if one color contains important text and the other color is used as a secondary accent, or if one color contains a design element that would be very noticeable if not positioned correctly.

1. Offset crop marks

2. If printing multiple copies on one piece of paper (e.g. 2-up, 4-up), set up your design to share edges that don't bleed (or when design allows) to minimize # of cuts, and area of paper and photopolymer needed. For example, the designs below bleed only on the sides, or have allover patterns that can run directly from one piece to another.

2. Share non-bleed edges, save paper

Some bleed designs can easily share edges

After printing: How to Trim Bleeds
Once you've finished printing, the only thing left is to trim.

If prints vary a LOT in where they fall on the paper, try hand-trimming 2 perpendicular edges (like cuts 1 and 2, below) to get a square edge that you can then use in the paper cutter:
Sample trimming sequence

If using the blue paper cutter in the back of the studio, plan your cuts so that the last edge cut is as long as possible, such as the sample trimming sequence above. The shorter the edge against the back of the cutter, the more the paper stack can rotate as the blade cuts, resulting in un-square cuts (e.g. rectangular business card becomes a trapezoid).

Hopefully, these tips will help you make the most of your printing skills so that you can minimize the time and effort it takes to print designs with a bleed, while enjoying the visual impact it can add to your prints.

After trimming
 I'm finished.  ;)