Cryptic crossword No 61

This should be a fairly gentle crossword for the most part, with a number of slightly harder / more technical clues. This is my first attempt at including a theme of sorts. Any feedback is most welcome!

I really enjoyed this thanks. Some lovely clues, not least 3D!

Thanks ABW for this crossword. I agree with Guava that 3d is particularly good - I love that kind of thing! (Though I needed the annotations to reveal its charms.) I also like the surfaces of 1a, 26a, and 1d. Well done on incorporating a theme. I got 23a and 24a early on and had an inkling the theme would be something else for a while.

Excellent work abw, and as you say, a more gentle ride than some others on here! Liked the theme... (SPOILERS - cont.)

Very enjoyable, thanks abw. Agree with the above comments on 3d, other favourites were 11a for the definition and 26a for the neat anagram.