Creating art for close traps

I will be having some cuts made, either mag or copper in order to print a two color piece. (see attached artwork)
It will have tight traps and if it is not in real good register some places will overprint where others are shy, showing a white gap.
My question is: Does anyone have any suggestions about how to see up this art work so that the traps are good. Should I scant all of the artwork so that it actually doesn’t touch, or should I scant only one of the two colors.????

image: Quilt 2 copy 2.jpg

Quilt 2 copy 2.jpg

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That is a tough one, Steve.

Normally, I would extend the light color under the dark color. The problem with that in your design is twofold: The first problem is that the purple is not that much darker than the blue, so where the two colors overprint, there will be a slight line which is darker than either color. However, you could minimize that by using opaque white in the formula for the purple, so that it would hide the blue better, where the blue is under the purple. The second problem is that where the lines intersect in the middle of the design, you would have to make the blue lines wider in only those places, so that they would extend under the purple lines. If you did that, however, and you got it out of register, you could slightly see the areas where you expanded the blue lines. (You could minimize this potential problem by making the blue which runs under the purple in those areas, slightly narrower than the purple line which it runs under).

Even though this approach may have its pitfalls, I think it is probably the safest way to go.

I would not cut back all of the artwork so that it doesn’t touch, because then, unless you can maintain perfect register, you are going to get different widths of white between the colors, and that is going to be very noticeable.

Geoffrey’s advice sounds solid (pun not initially intended!) I have provided vector artwork with basic separations for two and three-color work with no chokes or swells to Hodgins Engraving and have had really good results with their magnesium dies. One really important thing is to have your stock cut true, and to keep track of which edges are the gripper and side guide. I have spoiled a lot of stock with nearly perfect feeding of out-of-square stock. Allow for plenty of pieces to get position and for run-ups.
Jim DiRisio
The Norlu Press
Fayetteville, NC

Jim and Geoff,
Thanks for the input. I’ve been printing for over 30 years a typically try to avoid creating designs that have tough registration “tell tales” built in. I’ll do a variety of things to trick the system. On this one I want to challenge myself.
I also have 40 years in the paper business. It is nice to see that you, Jim, understand the importance of keeping a common gripper and guide from the cutter to the press.
Keeping these consistent along with not rotating or flipping over any of the lifts can be critical when trying to achieve tight registration. This topic typically brings all kinds of reports about how true and square people say they can cut, but the truth is they can’t.
Still looking for a way to make this work.
PS- printing on a 8x 12 C&P NS.

send this job to someone else, that’s the easiest way to do it.

Good idea, Dick!

One other possible source of misregister on a hand fed press would be if the face of the gauge pin which the paper feeds up against, is not at an exact right angle with the platen. If that was the case, and one sheet happened to hit the gauge pin down low near the tympan, and another sheet happened to hit the pin up higher near the tongue, the position of the print on each sheet would be slightly different.

As Jim DiRisio said above, maybe you could get away without spreading the blue, and just do what we called “butt register,” where the colors just butt up against each other, (and hope you get a tiny bit of trap because the ink squeezes out on the paper a very small amount). If you do this though, I would think your platemaking process, or your engraving house’s platemaking process, would have to be very precisely calibrated so that the line thickness on your plates comes out to be EXACTLY the same as the line thickness on your art.

Thanks Guys,
Dick, it’s my own project. No sense in sending it out. The goal is to challenge myself and my press.


What’s the scale? That’s very important and is a piece of the puzzle which is missing before I would hazard advice.

Haven the piece measures as a rectangle (diamond) 4.5 x 5.5, as a square 4 x 4. The thickness of the bands are just over 1/2 inch. Looking for ideas.

One of our fellow printers wrote me regarding as simple system of getting imposition on press. Here are few pix from my collection of the process.


image: tranlucent poistioning 4.jpg

tranlucent poistioning 4.jpg

image: translucnet positiong 4.jpg

translucnet positiong 4.jpg

I wouldn’t personally try to mess with adjustable gauge pins and/or overlays for something like this. Too many variables.

I attached a photo. Here’s a small card printed on black museum board.
Wherever you see the red, there is actually gray behind it. Nailed it pretty much, can’t actually see the gray sticking out from behind it at all.
Slightly different trapping situation but I used locating marks to mount both plates and it did great. This was small but I’ve done it with up to 8x10 plates so you shouldn’t see an issue, I would think.

I don’t rely on eyesight or adjustments, but rather locating marks built into the plate around it. You will have to design your own, but some targets in a grid around the image at corners and centers in the traditional places should locate it for mounting pretty effectively. You’ll have to hit a mounting sheet hard enough that it does leave an indent. Then you can ‘fit’ the next plate into this indent, keyhole. Use some doublestick tape to hold it in place around the image. (The tape comes off later.)

I work with polymer, and for something like this it would probably be my preferred route to cuts.

image: IMG_0970.JPG


Steve…..I know that’s not your hand in the pictures, but if that person happened to tie string across the gripper bars to hold the paper down, his ring could easily get caught on the string. If he used weak string as he should, I know he could probably break the string by yanking his hand out, but stull, I wish people wouldn’t take chances like that.

Geoffrey to be fair, he doesn’t look like he’s feeding in that photo

If you create your art in Illustrator you can make your trap by adding a stroke. Make the objects touch with no stroke for kiss, or butt register. Add a stroke to both colors to create a trap. The stroke width equals the trap.

image: kisORtrap.jpg