Flat, even.
even
level
Legato
You iron to smooth fabric.
I think they want dice but that's not really right because one of them is more properly a die.
bumpy, rugh
Heist.
The word meaning "not smooth" is spelt rough.
Smooth
it's a small Mexican dog that has smooth hair
level, soft, steady, shiny, gentle
Other words for 'flat' are... even, level smooth, equal.