noun / verb
pucker
PUK-er/ˈpʌkər/
A tight fold or gathered shape, or to form one.
The tight stitching creates a small pucker in the fabric.

Etymology
Pucker may be related to pock, meaning “bag” or “sack.” If so, the image is like pursing a money bag: drawing its opening together gathers the material into folds.
In context
because the fabric is quite light it doesn't Ripple doesn't pucker two layers makes a really neat seam
More examples
- She puckers her lips to blow a kiss.
- The fabric puckered along the seam after washing.
- He smooths the little puckers around the waistband.
Forms
pucker · puckers · puckered · puckering
Similar words
- wrinkle
- A broader term for folds, without necessarily suggesting tight gathering.
- crease
- Usually suggests a distinct fold line rather than gathered material.
- purse
- Specifically describes drawing the lips together into a tight shape.