PERFING with a jacket on the windmill

I just wanted to get a second opinion on perfing with a jacket on a windmill. We are not sure if we need to protect the jacket with something or if we just perf directly onto the jacket with minimal pressure. Well, enough to get through the stock at least. Thanks so much for your insights.

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Key in to Google, *Letterpress perforating system Holroyd* comes up, same subject on B. P. 3rd. June 2013, i.e. Jesse A.,s! query? 22 replies and counting, my humble effort but the best as well!!!! Look it up, please. Mick.

Just let it kiss the jacket.

Unless your reference to the “jacket” actually involves the tympan/packing, there’s no reason not to use perf rule directly on the die-cutting jacket—that’s what it’s there for.

Now, if you mean to die cut on the bare platen—well that’s considered a no no, as it will damage the platen surface, leaving grooves and such that will “telegraph” through packing and effect printing, especially on larger solids.

If you do mean to perforate on top of the tympan, there is a product called “Perf-a-Base” that is designed for this task, it is meant to be pasted to the tympan and is meant for use in mixed (perforation plus printing) forms. Low rule (.909 or less) is recommended to prevent the rollers from being nicked or inking the perf rule.

Thanks everyone! Just wanted to make sure we weren’t supposed to protect it with shim tape or something strange. We have a brand new steel jacket, and I didn’t want to mess it up right out of the gate. We will go with a little kiss. Thanks again. I will have more questions when I get to die-cutting. Not sure how to nick and how much to nick the die, or if we even need to!! If you have a good video or ref. for this, I would truly appreciate that as well.

more that may be of use to you “937die”

I hope that these pictures will help a little bit. We usually use this die-cutting jacket. The other product is used for simultaneous printing and perforating, but the perforating rules should be lower than the distance from the rollers as mikefrommontana mentioned.

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You can also tape a steelrule to the regular paper packing in case you need to perf and print at, the same time

In this case you woul use low high perf rule so you dont damage the rollers and perforeate horizontally


repeat of an earlier post
Die cutting and perforating on H platen
Press is designed to print with .918 type and a total of .040” on the platen including stock to be printed. To die cut with.918 rule you need .040” on the platen not including the stock to be cut. Most letterpress folks use .909 perf to protect the rollers when printing and perfing at the same time, often that is the only perf they have on hand but it requires .009 added to the platen just to get it to print plus the thickness of the stock to get it to cut. Banding iron and tape is one way to do this. A micrometer and various thickness of card stock, paper and metal and an understanding of the pressure control of the press is the key to success.
To use the die jacket when perfing only is up to the operator. The cut or perf rule should never bite into the jacket or damage the bed. Into diecutting using wood or poly is for the leather and related industries. I have had crease and perf rule ground to .888” in order to perf crease and print at the same time no ink on rule no damage to rollers.
I sell dies to clients that use H platens for diecutting they get .918 cut because that’s all they ever knew. I make my own for my platen using .927 down to .910 depending on the density of the stock to be cut or kisscut. .927 cutting rule in a folding carton die gives me .010” extra space on the platen for matrix or any surface makeready.