abstract
alloy
aluminum
background
banner
bar
board
border
construct
construction
dark
design
dirty
format
frame
framework
gray
grunge
hard
industrial
industry
iron
line
material
metal
metallic
old
panel
pattern
piece
plate
rivets
rough
rust
rustic
screw
sheet
shine
silver
space
stainless
steel
stripe
structure
surface
tablet
template
texture
wall
worn