wrinkling

(materials) Distortion occurring in a film of paint that gives the appearance of ripples. Development of a roughened surface on a film of sealant. Also known as crinkling; riveling.
(metallurgy) Waviness around the edges of a drawn metal product.

1. The distortion in a paint film appearing as ripples; may be produced intentionally as a decorative effect or may be a defect caused by drying conditions or an excessively thick film.
2. The crinkling of the surface skin of a sealant; affects its appearance, but usually not its sealing capability.