The unclued lights (two of two words, and the rest paired) are of a kind.
 

Across

1    Book with smears around comments on jackets (6)
7    Fashions in stationers (6)
11    Made supple, brewing old-time ale (10)
14    US novelist left out, downstairs (5)
15    Wife and marine attacked telegraph fitter (7)
17    One of England’s winners in Moscow — or loss! (7)
18    Articles on Monteverdi’s first choral work (6)
19    Tax is small on poet’s little home (4)
22    Boy rejecting green and gold in France (6)
24    Jumpers touched, we’re told, by president (9)
25    Short film translator leaves passenger plane (5)
26    Athenian cavalry commander thrice cut these groups...