.PATTERNS File Extension
What is a PATTERNS file?
Patterns library created by Corel Painter, a drawing application used to create digital artwork; contains one or more patterns that can be added to the Painter canvas; may include Piano Keys, Floral Fabric, and Lace Ribbon patterns.
You can apply a pattern to your canvas. They are similar to other Painter media such as Weaves, Looks, and Gradients.
NOTE: The .PATTERNLIBRARY file is more commonly used by Corel Painter than the PATTERNS file.