Solvers! Thanks for giving my puzzle a try, I hope you enjoyed it. Let me know how you got on in the comments below, and feel free to follow https://crosshare.org/tuber for more like this. Here's the wash-up:
ACROSS. 1A. homophone of "dull palette" = GREYS/GRAYS.5A. "Thank you" = TA + last letter of "Gordon".6A. Reversal of "and so on" = ETC, contained in "books" = OT (old testament.)8A. Cryptic def.9A. "Sail into the wind" = TACK + first letter of "yachtsman".
DOWN. 1D. Good = G + crowd = HOST.2D. anag. ORC.3D. Reversal of "Italian city" = CITTA.4D. "Venture" = TRY, supporting last letters of "sustainable" and "fashion".7D. Hidden reversed in "pinKLEgwarmers".
I saw it as an adjective meaning "related to Athens"; attic is the dialect of ancient Greece that was spoken in the region of Attica, closely associated with the capital, Athens.
Glad you enjoyed it :) My dictionaries give this definition for "Attic": "of, relating to, or having the characteristics of Athens or its ancient civilization."
My definition is therefore not "Greek capital" but "from Greek capital."