noun
unevenness in paint or coating
Refers to blotchy, streaky, or inconsistent application of paint, varnish, nail polish, etc. Common in DIY, crafts, and cosmetics contexts.
壁にペンキを塗ったら塗りムラができてしまった。
When I painted the wall, I ended up with uneven patches.
マニキュアの塗りムラを直すのは難しい。
It's hard to fix unevenness in nail polish application.
Compound of 塗り (nuri, 'painting, coating', from 塗る nuru 'to paint') and ムラ (mura, 'unevenness'). The katakana spelling ムラ is conventional for the 'unevenness' sense.