A perforation is a small cutout in a material. There is usually more than one perforation in an organized fashion, where all of the cutouts collectively form a perforation pattern. Perforations can be used as guidelines for ripping thin material along a perforated line or used as a design element for functional or aesthetic purposes.
In other cases, such as the usage of perforated materials in splints or casts in medical environments, perforations are used as a means to make a material air and moisture permeable. Re-cast as well as orfit are two companies who make use of perforated sheets for their splint applications. These sheets are thermoplastics, meaning they turn malleable and deformable when heat is applied. The perforations in the sheets enable it to stretch and adjust to the user's anatomy resulting in a best possible fit.
This works as followed. A hex grid with a predetermined number of cells is created. The middle points of each cell act as the center point for whichever perforation pattern is selected. The attractor (line, curve, point, circle, any geometry) determines the scaling of the pattern within the hex grid cell.
The closer to the attractor geometry a cell and the perforation pattern is, the bigger it gets scaled. The result is a flexible part right along the attractor geometry. Directed movements can be made possible by choosing and drawing attractor geometries. A simple result is a straight line causing a linear bend, however much more complex deformations are possible.
Apart from circular or hexagonal polygon perforation patterns, shapes derived from the three pointed star work best in a hexagonal grid. The gaps in between are best distributed and the three axes allow for the most range of movement. In adding a fillet, a capped end and rounding the geometry altogether it increases the range of movement, reducing the remaining material after the cutouts.
Circular and hexagonal cutouts take away more dense areal material which is prone to tearing along the bridges.
