What are rounded corners? Rounded corners (box corner radii): The radius of the rounded corner die on the cutting die determines the curvature; the radius (R value) of the rounded corners is matched to the box type and specifications — large boxes are paired with a large R, and small boxes with a small R.
How can this be verified? When producing a proof, inspect the rounded corners (curvature and burrs) and feel the edges (smooth and not rough to the touch); conduct a trial run before mass production. For small-batch verification of rounded corners, produce a proof first before placing an order.
The rounded corners of a packaging box represent ‘the tactile sensation in the details’: the correct R value, a clean cut from the die, and well-sealed edges and corners — when the rounded corners are executed with precision, the box feels refined to the touch.
What goes well with rounded-corner boxes? Ensure the rounded corners of the box (lids and bases) align perfectly: the smooth opening and closing of a rounded-corner box, along with its warm, inviting appearance on display, are key selling points.
Rounded corners are the ‘softening’ detail of a packaging box: right angles convey a sense of robustness, whilst rounded corners convey warmth; they offer two distinct tactile sensations when held in the hand — but if the rounded corners are not cut properly, with frayed or curled edges, this actually detracts from the product’s value. This article clearly explains the key points of rounded corner processing.
How should the die be set? The die for rounded corners (corner-cutting die): the sharpness of the die (for a clean cut) and the pressure (to cut through without damaging the material); for irregularly shaped rounded corners (elliptical, large arcs), a test cut is required.
How can curling be prevented? Curling at rounded corners (fuzziness or delamination of the paper edges): Rounded corners on thick paper (greyboard) are prone to exposing the paper core — edge pressing or sealing (applying edge varnish or heat-sealing); after lamination, the edges of the rounded corners must be smooth.
