Trimming paper down

I’m having issues with trimming paper after I print. I cut paper to be an inch on both sides larger than the block, and have just started using crop marks. what seems to be happening is that the image isn’t square with the edge of the paper. i checked my cutter by putting a piece of paper in on both ends of the blade and they are of equal length, so I know my cutter guide is straight. I’m thinking that the paper, when fed into my c&p 8 x 10 isn’t level and was wondering if you all have some tricks to keeping everything level and at a 90 degree angle. I’m fine printing, but when it comes time to trim the work, I’m a basket case and don’t want to do one at a time - more like a stack of 20 or so. Any suggestions would be greatly appreciated!

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Making sure the paper is squarely placed when fed into the press is critical. I take lots of measurements and adjust the guage pins accordingly until it prints exactly where I want it (assuming I’ve fed the paper correctly into the guage pins). Always use the same two edges on the guage pins if printing more than one color.

You don’t say whether the distance the image is off square is consistent from sheet to sheet. If not, it was a feeding problem…inconsistently hitting the guage pins with subsequent sheets. Cutting one by one is the only option here.

If it is consistent, measure the amount of difference between one side and the other. Then you might be able to build a shim against the back fence of the cutter to offset the difference. Once you have one side square to the image, remove the shim and trim as opposite side normally. If you have a side guide the remaining two sides are easy. Otherwise you’ll need to rig up some sort of guide. This assumes your cutter really is cutting squarely.

Unless I’m forced into printing with a very narrow or no margin, I’ll cut the paper to size before printing.

Thanks Arie - your tips are helpful. It may be that I’m not consistently feeding the paper square, & was hoping for some “trick-of-the-trade” suggestions. I’ve pretty much covered the above. I wonder if back in the day, they printed on c&p’s with paper cut to size or did they trim afterwards?

Both. Depending on the job’s particular characteristics. Feeding uneven paper, such as deckle edged or unevenly cut paper on a platen is a real pain. You want a stack of evenly cut, uniformly sized paper or you want to be printing on a hand or cylinder press with different registration systems.

I usually cut to size first, but as my cutter is not one of the most accurate, I’ll also trim afterward if needed. If the leaves have been bound into a booklet, at the very least the fore edge will need trimming after binding and folding. The inner pages of a signature will naturally stick out. The thickness of the paper will assure that.

The ‘trick” to printing squarely consistently is to be very careful in your setup and then very consistent in your feeding. Both take lots of practice.

BTW, your press is either a 8x12 floor model or a 6x10.5 tabletop. C&P didn’t make an 8x10. A 7x11 for a short time, but not an 8x10.

it’s an 8 x 12 floor model - though I do have a 6 x 10.5 tabletop as well. i refer to it as an 8x10 cause’ i forget. thanks Arie! On this job, I’m taking my time feeding, hopefully it will work to my advantage.

For the first cut you should be placing the paper’s gripper edge against the backstop of the cutter, the second cut should be with the paper’s side guide edge against the backstop. After that, everything should be square.

Thanks alncarter! I’ve been doing it the opposite…I think. I put the vertical (side guide??) against the backstop first then rotate clockwise, so then the horizontal (gripper edge??) goes to the backstop second. maybe this will make a difference.

You do need to put the first cut edge against the square side of the cutter (usually the right side) for the second cut and be sure the cut edge is fully against the side, or your second cut may not be square to the first.

No comments regarding cutting paper.But here a little hint to setting the gauge pins correctly first time.
When I have changed the packing on my platen press I lock up two brass rules in an ankle of 90 in center of the chase. Following I make a print on the packing – I know that I owe you a beer! Now I have two fix points/lines on the packing regarding to the press and chase where I can mount my gauge pins.
Gott grüß die Kunst
Jens

image: The gauge pins and the lines on the packing.JPG

The gauge pins and the lines on the packing.JPG

image: The chase with the brass rules.JPG

The chase with the brass rules.JPG

jens! what a great tip - thank you - i will certainly do this!
thanks AdLib

It’s a common practise to pull an impression on the topsheet and wipe off the ink with some typewash and baby powder. This gives you an excellent guide using the actual print from which to set the gauge pins and adjust your margins.

Rich

Front Room Press
Milford, NJ
http://frontroompress.com
http://frontroompress.blogspot.com

thanks Rich, I do this - but use my tympan for several diff. cuts and it get’s too confusing…though I will try the baby powder- never done that before. Thanks!

you may find it worthwhile to make a setup sheet at the beginning of your ‘job’. on this sheet you should mark the corner you use to register your pins to the sheet (this is called a jog corner). If you’re doing a multiple color job, you should make sure to only use this corner in order to insure that your paper is consistently registered.

it’s really easy to run into trouble quickly if you’re dealing with sheets that are cut in lots smaller than your total edition size. although not always possible, it’s best to have all of your sheets cut down to size professionally (machine cutter that can handle a large number of sheets) so that every piece will have the same cut edge (if a couple of sheets are cut slightly off, it will cause them to be slightly off register in comparison to the others).

If you can’t get everything cut down this way, try to at least keep the natural edge on your sheet intact. By this, I mean planning your cuts in your trimmed paper to take advantage of the straight edges of the paper… the cuts that the manufacturer made rather than the ones you made in house.

keep working at it, and don’t let it frustrate you! It’s better to take your time and cut individually or in small groups than it is to accidentally cut an off register print through the image area!

(oh, and with large loads, shear style cutters tend to pull the paper towards the sheer, which can cause the cuts to vary from sheet to sheet)

thanks vroom- i’m noticing that you can run into trouble quickly. I’m also noticing that when i’m feeding my platen, the sheet rests on the pins diff. from sheet to sheet. the pins have a slight tilt to them, and that little fraction of space from one print to another is also an “issue” I have megill spring tongue gauge pins - and wondering if i should switch those out to something with more of a 90 degree to them. also, i have a 26” challenge cutter - & cut stacks in quantities of 30 or so at a time. but have been thinking maybe i should get a good shear cutter so i can see better and trim individually if something got too wonky on press.

As you’ve noticed, if the sheet slides up the face of the gauge pin, you’ll have inconsistant position. With any gauge pin, it is important to set it square to the sheet, that it’s face is perpendicular, and that the tongue sits as low as possible (without preventing proper movement of the sheet). Needle-nose pliers can be used to re-form a bent gauge pin, or put a curve in the tongue. Or a paper match or bit of pipe cleaner can be placed in the tongue-hole to lower the tongue.
Personally, I like the Megills Twin-grip gauges or the Gardner or Kort quad guides. Either can be repositioned easily for slight changes in register and don’t slip (when you follow the instructions).

thanks parallel_imp - the one’s I have come with an angle to them, so I figured that’s the proper thing. seems wrong to take pliers to something brand new and bend it to a 90 degree… i’ve heard that kort are good ones, though pricey. i had double grip at first, but smashed them & ruined a very expensive plate :(

I haven’t seen the new Megill product; their original spring-tongue gauge pins were quite square. But even when the face is angled, if the tongue is held down and comes out close to the tympan, then the sheet will hit the same spot on the pin and you should have tight register. If there’s enough room for the sheet to slide up the pin (or curl up for flimsy stock), you’ll just get coarse register.
I’ve fixed a lot of twin-grips with pliers after minor smashes, but there’s not much you can do if it hits a plate base, except save any good parts, like the nuts or the base. You may come across others that lost a nut, or a screw from over-tightening. Korts on the other hand wear out and there isn’t much that can be repaired.

You’re probably doing this already but I thought I’d mention it just to cover all the bases: At the bottom of the front edge of the gauge pins where the paper rests are two small nibs. Once the gauge pins have been adjusted where you want them they need to be set by tapping on them lightly to drive the two nibs into the topsheet. If this isn’t done then the pins would be held up slightly at that edge and possibly cuse the problem your’re describing, not to mention move around.

Rich

Front Room Press
Milford, NJ
http://frontroompress.com
http://frontroompress.blogspot.com