abstract
background
black
bw
centric
centrifuge
centripetal
circular
colorless
concentric
contrast
distorted
distortion
effect
geometry
graphic
grayscale
greyscale
illusory
illustration
irregular
lines
minimal
misc
miscellaneous
monochrome
monocrome
optical
pattern
radiating
rotation
stripes
tension
tweak
twist
uncolored
visual
warp
wavy
whirl
whirligig
whirlpool
white
zag
zig
zigzag