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Small-format folding is used to convert everything from bottle hangers to clothing tags and pharmaceutical inserts. It's performed on a buckle folder, which uses rollers to push the paper and make it buckle at a particular point. This exerts a great deal of force on the "push" edge of the sheet. When a sheet is bent beyond the point of elasticity, ripple cracking is the result. This ripple is a permanent fracture in the surface of the sheet approximately 1/2" after and parallel to the fold. Ripple cracking compromises the appearance of the sheet, so it's important to plan projects carefully to avoid it.
 Select stocks carefully
Most stocks will start ripple cracking at 10pts or thicker when folding against the grain on a buckle folder. When folding with the grain, ripple cracking usually starts at 12pts. Exactly when problems occur depends on paper characteristics and the manufacturing process. In general, the "softer" the sheet, the more likely it is to resist ripple cracking.
On some sheets, ripple cracking will occur along the entire sheet, producing an "alligator skin" appearance. This is the result of the sheet being bent beyond its point of elasticity during folding.
The Rickard Advantage
Plow folding heavy stock doesn't bend the sheet, and therefore won't result in unsightly ripple cracking. However, plow folding may reduce your folding sequence options, so let us help you plan your job appropriately. Rickard Bindery has a wide array of equipment and experience to handle all of your folding needs.
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