This crossword No. 1160 clues and answers were published on Sun 24 Dec 2017 and the puzzle can be visited by following The Guardian Speedy Crossword No. 1160 link.
All Across Clues and Answers:
7-across – Developing surface film; sheen : PATINA
8-across – Net made by a spider to catch insects : COBWEB
9-across – Young seal : CALF
10-across – Transmission of recognisable characteristics to descendants : HEREDITY
11-across – Rapidly and vigorously : FASTAND
13-across – Revert : LAPSE
15-across – Dissertation : ESSAY
17-across – See 11 : FURIOUS
20-across – Tries to improve what is already beautiful or excellent : GILDSTHE
21-across – See 20 : LILY
22-across – Be relevant to : BEARON
23-across – Join, meet with : LINKUP
All Down Clues and Answers:
1-down – Spanish port and resort town : MALAGA
2-down – Minor quarrel : TIFF
3-down – Rakish : DASHING
4-down – Nut of an oak tree : ACORN
5-down – Largest member state of the UAE, and its capital : ABUDHABI
6-down – Slightly more aggressive disagreements than 2 : SETTOS
12-down – Hither and thither : TOANDFRO
14-down – Euro ale? : AUREOLE
16-down – Harpsichord-like keyboard instrument : SPINET
18-down – Mark put over a vowel in German to indicate a different quality : UMLAUT
19-down – Con: leader singer of Police : STING
21-down – Air bag? : LUNG
This crossword has in total 24 where 12 are across and 12 are down.