how to score and perforate

I have 4 perfing/scoring/diecutting jobs under my belt and one this weekend… All you really need is a good sheet of hard metal (or sheet metal) to tape onto your platen and make sure the press is leveled correctly to accomodate the space. It took me a few times of messing with my press bolts and knock on wood, Im set now to quickly switch between diecutting/perfing/scoring and printing. Oh yea, as for not messing up your rules and stuff, that would be how hard you are hitting it. And for scoring, make sure you have the correct one-time plastic strips that go on there. It’s fun and easy. (there’s good instructions in list archives for that as well)

Here’s a long post, crossposted from PPL today from the Letpress archives long ago, by Mo, who helped me with my diecutting (he sold me a piece of metal to use as a “jacket”). It has all you need to know and then some. Oh yea, take off your rollers!

Date: Fri, 2 Aug 2002 13:10:01 -0600
Reply-To: Letterpress Discussion List
Sender: Letterpress Discussion List
From: Leonard W Molberg
Subject: Die cutting - a short primer - it’s not that difficult!
Content-Type: text/plain; charset=us-ascii

I’m surprised at some of you who haven’t tried it. It is really quite a simple process, though, like printing, can have it’s challenging moments.

It’s really nothing more than a straight knife edged rule which, if serrated, would be a perfing rule. I assume you all perf occasionally. Use a perfing rule against the side of another rule and you’ve the simplest, cheapest and sometimes best perfing setup.

Die cutting is similar, you just do it, more often than not, in other than a straight line. If you want to just slit something just use a piece of cutting rule like a perfing rule.

You need three things - a letterpress, a steel rule die (usually made by a die making specialist) and a die cutting plate or jacket. It can be done on a cylinder, but I’ll stick with platen presses here (I do almost all my die cutting on Kluges)

A simple piece of stainless steel sheet, about 20-22 gage, will slip under the tympan inplace of the pressboard. If your platen is set fairly
high you will probably want to order the die with .918 rule, but .937 seems to be more standard for die cutters for some unknown (at least to me) reason. A piece of mild steel sheet will work, even cut from the
bottom of a galley, but the die seems to raise a ‘burr’ on it which fights you when pulling the piece out. Stainless doesn’t seem to do that for some reason. You might be able to get a piece from a local sheet
metal shop, cut to your platen size.

For narrow dies, you can tape down the side of a perf or cutting or scoring rule to cut against with good results.

If you decide to spend more ( a LOT more!) money, you can order a hardened and ground steel die cutting plate for your platen, but for simple jobs the cheaper plate is quite adequate. If you’re careful about your
impression and makeready, you will not “emboss” the plate and it can be reused hundreds of times. Even if you slightly impress it, it probably won’t keep you from reusing it. I’ve seen some in pretty bad shape and still serving well. If you get careless, well…it’s just like getting careless any other way. Bring up the platen packing underneath until the
die just cuts properly, level the platen with the platen screws if necessary, then if any piece of the die rule doesn’t want to quite cut, makeready under the bottom of the die with “lick and stick” gummed
stock or tape or whatever you wish, just like bringing up a low spot of your type from under the type, rather than trying to makeready under the tympan.

You can also have combination cut/score dies made, but it gets more complicated, as you have to consider the stock thickness and order the score rules appropriately high. On cylinder presses, the dies need to have higher rules in one direction than the other, so it pays to start simple.

You can put the plate under the tympan, bring up your packing until it just “clicks” through the tympan, then cut a margin around the die area (preferably after setting your gage pins) then tape around it with
Scotch tape just outside the die area. If your clearance is too tight, fasten the plate down on top and double sticky tape home made gage pins of 6 pt slugs to the plate. I do this all the time, the Scotch double sticky
tape is thin enough that it doesn’t cause problems and it stays put even with the press at higher speeds. You can double sticky tape a “tongue” made of 2 pt lead to the top of the slug. If you nick that kind of gage pin or tongue, you probably won’t damage the rule in the die.

Lock up the die just as you would any other job and, of course, remove the rollers from the press before you die cut.

If you have a real problem getting the sheet out of the press without it coming apart, you can “nick” the rules slightly to provide a very thin bridge to hold the sheet together, but when hand feeding it should
not be a big problem.

You’ll figure out things as you go, but it’s really a fairly simple operation, especially things like circles, windows in covers, and other simpler shapes. You can even cut your own rules for rectangular or square holes and lock them up just as you would any other form. If your lead and slug cutter is good and sharp, you can cut rule on the back side without hurting the cutter, then you can slighly bevel the ends on a bench
grinder to get a tight corner. Then, if you wish to keep the setup you can cut wood and glue around the rules, using your chase and quoins to clamp them while glueing. I have several home made dies made this way.

You will need “corking” or ejection rubber around the rules to keep the sheets from sticking on the cutting rule, especially in corners or holes or whatever. You can use half inch thick weather stripping rubber
with a sticky back with good success, though die makers have many special types of “corking” available to suit the application.

Rolodex cards are easy to die cut with a good die, but harder to get out of the sheet due to the little slots in the bottom wanting to hang on. I have my rolodex dies made with a rule clear across the bottom, then the small pieces come out over a home made “striping” die with a home made punch and hammer. I just finished a 43,000 run of 2-up door hangars and have a simple stripping die made of a piece of die board (plywood or anything else) with two holes slightly larger than the punched hole, set up in a spare chase with a few reglets sticking up at approximately the gage pin locations. This allows me to punch out a whole stack of holes. I try to keep the die set up to allow the piece to come out whole, then break out the die cut places in stacks.

Be inventive. I’ll try to answer questions if you have any, as would probably a hundred other list members.

Mo

great tips thus far. i must admit that i have scoured briarpress and could not find any adt’l info re this bit above “…and for scoring, make sure you have the correct one-time plastic strips that go on there…”. aka where do i get some or do i make them?
also, does anyone have any photos of how the die cutting set up looks when it is on a platen press? thx svb

Ah… Scoring Matrix. It’s a one-time use plastic strip that you put on the scoring rule, then you close the platen and it sticks on the tympan creating a base for the paper to crease into. Fritz sells it at NA Graphics.

http://order.nagraph.com/cutting-scoring.html

If you have access to the letpress archives, there’s a great post on creasing from Phil Ambrosi. I can’t find it now.

Updated. thank you, jason (& fritz).
i completely overlooked the “scoring” tab on his site, somehow. i had only tried a keyword search without a result because they are id’d as “creasing matrix” (for anyone in the future). off to the archives…svb

Has anyone ever scored on both sides before? I’d assume you’d have to do this in 2 runs. I’m trying to score a long invite using an accordion fold. 4 panels with 3 folds so it would fold out then in then out again. Any thoughts or insights would be great. Thanks.

Cheers,

-chris-
moxie press & co.

You can do scores for different directions of fold in one pass. Use creasing matrix for the outside of the score and string-and-rule for the inside of the score.
The string-and-rule method uses two creasing rules a certain distance apart, depending on stock thickness, and a string fixed on the topsheet right between the rules.

Ahhh, I gotcha. so the string sits under my paper, maybe taped to the tympan and 2 rules impress around it. That makes sense. Thanks for the help parallel_imp!

Cheers,
-Chris-

Chris, you really don’t have to score on both sides, the paper will fold either way if you just score from one side. Dick G.

True enough, but some stock will crack if folded the wrong way from the crease. The point of the rule-and-matrix is to stretch the fibers on the outside of the fold so they will bend without cracking. It can be critical with cover and coated stocks.

Many years ago I was taught that the bump is to be on the inside of the score. It is counter intuitive.
Look at the panel folder cards at the paper supply store. The bump is on the inside.
This may get a good argument going as some printer will say that she or he has always done it the other way for 50 years.

My main business was numbering, perforating and scoring and die cutting for copy centers and other printers. Everyone had a different view on scoring, some wanted it scored from the front, some from the back, some wanted it barely to touch the paper, some wanted it scored deep. I’ve been doing this now for 50 years and i still don’t have a clue what way is right, i just try to score without breaking the stock. Dick G.

I know what you mean about the argument on which way is correct. Guess it depends on what works on each job. We’ve used some inside, some outside, some with matrix, some without. And some stock will crack if scored across the grain instead of with the grain. That’s why I like a windmill for scoring… because of the impression control. Ron

Dick, I dug this up from a 1989 instant print magazine. You don’t want the paper to get stressed out.

scoring.jpg

You mean i’ve been scoring wrong all my life!!! I almost always score so it folds the incorrect way. Guess i’ll have to change my ways. Thanks Dennis, Dick G.

Nice to know I got something right. Guy who taught me knew his stuff.

Some really thick paper (cardboard) works just the opposite but I doubt anyone would be doing that on a small letterpress.

How do I know what size creasing matrix I need for each rule?

Size your Creasing matrix to the stock. Wider and deeper for thicker paper. http://cartoncraftsupply.com/contact_us.asp will send you samples to try.