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A perf on the lead edge can be
closer than a perf on the trailing edge. |
Perforations and scores are used to create weak spots in sheets of paper to assist in folding accuracy and quality. In both direct mail pieces and product inserts scores and perfs are often used in tandem. The score ensures the fold will be accurate, while the perf allows for a portion of the product to be easily torn off and either returned or kept by the end user (i.e. warranty card, coupon, or postcard).
The distance between perfs and scores is crucial because if they are placed too close together, it can cause problems. Both scores and perfs weaken the paper and as we all know a buckle folder will seek out the weakest spot to make the fold. Since a perf is inherently weaker, a fold sequence may be compromised if the perf is set too close to a score because the perf will “buckle” first leaving the score unfolded.
At Rickard Bindery, we process a lot of product that ends up going through the mail including reply envelopes for publications that need to remain intact after the envelope has been removed. For most direct mail, the standard distance between perfs and scores is usually 5/16.” But as with most bindery operations, paper choices lay the foundation for what will and won’t work.
Production Tips
Here are three different ways that affect how close the perf can be to a score and still get it to fold on the score:
1. Thickness of the sheet. On a thick sheet of paper, keep the perf and score a little further away from each other. For sheets 5 pts. and higher, a good rule of thumb is to keep the perf at an absolute minimum distance of 3/8” away from the score. If your sheet is 50 lb. enamel and you press perf it, you can probably get the fold to occur within 1/8” of the perf.
2. Light and heavy perfs. Even the way in which a score or perf is applied can affect the recommended distance between the two. Die cutting equipment will provide the best flexibility in perfing and scoring options. The accuracy, consistency, and range in pressure that is used when applying perf/score assures your project the best chance of success. Press perfs may be subject to some variation and lack the same finesse when it comes to apply differing degrees of perf/score pressure as compared to the die press versions. But in many cases, the cost savings associated with press perfs, especially on light stock, make them a great option. Perfing and scoring on the folder is middle ground in terms of quality, accuracy, pressure. However, the pressure for folder perfs does tend to track toward the deep side of the equation, making the perfs weak. Depending on the project this may either be a positive or negative.
3. The direction of flow into a folding machine plate. If the perf is on the side of the score that’s going into the folding machine plate it can sit a lot closer to the score, than if the perf is on the push side, or trailing edge, of the sheet. For instance, it’s likely the fold can be made within 1/8” of the perf if it’s on the leading edge. On the trailing edge, the perf won’t be able to get any closer than ½” to the fold. That’s a difference in how the paper is bent as it’s being folded inside the folding machine. The principle here is that the side being pushed goes through much more of a severe bend in the process of making a buckle fold.
The Rickard Advantage
Founded in 1900, Rickard Bindery has been providing advanced folding and other post press solutions for more than a century. Rickard Bindery's services include miniature, oversized, map, gate and specialty folding, 12-pocket saddle stitching, attaching, loop stitching, seam, fugitive and remoistenable gluing, rotary scoring, personalized product handling, fulfillment, wafer sealing and automatic shrink wrapping.
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