Fabric weave (5)
'fabric weave' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for wale that I've seen before include "Texture" , "best Scotch?" .)
(Other definitions for twill that I've seen before include "Fabric with distinctive weave" , "Fabric weave with parallel diagonal lines" , "Stuff" , "Diagonal-weave fabric" , "Material" .)