選択的
abstract
attached
background
black
burning
chain
close
concept
connect
design
detail
grey
grunge
hard
heap
heavy
industrial
industry
iron
link
linked
loop
metal
monochrome
object
old
pattern
pile
power
protect
protection
rust
rusting
rusty
safety
secure
security
shape
shiny
space
stainless
steel
strength
stress
strong
symmetry
texture
vintage
white