What can you write on? Anything but the electronic version of The Times! (9)
I believe the answer is:
notepaper
'what can you write on?' is the definition.
(notepaper can be written on)
'anything but the electronic version of the times' is the wordplay.
'anything but' becomes 'not' (I've seen this in other clues).
'the electronic' becomes 'e' (as in e-mail or e-books).
'version of the times' becomes 'paper' (I can't justify this - if you can you should give a lot more credence to this answer).
'not'+'e'+'paper'='NOTEPAPER'
(Other definitions for notepaper that I've seen before include "Sheets for memos" , "Letter-writing sheet" , "Bond" , "Correspondence on this" , "Stationery item" .)