Antonyms of adj curly-grained

1 sense of curly-grained

Sense 1
curly-grained, cross-grained, wavy-grained -- (of timber; having fibers running irregularly rather than in parallel)

INDIRECT (VIA uneven) -> even -- (being level or straight or regular and without variation as e.g. in shape or texture; or being in the same plane or at the same height as something else (i.e. even with); "an even application of varnish"; "an even floor"; "the road was not very even"; "the picture is even with the window")

Similarity of adj curly-grained

1 sense of curly-grained

Sense 1
curly-grained, cross-grained, wavy-grained -- (of timber; having fibers running irregularly rather than in parallel)
       => uneven (vs. even) -- (not even or uniform as e.g. in shape or texture; "an uneven color"; "uneven ground"; "uneven margins"; "wood with an uneven grain")