Rips up 60% of the paper beforehand, eventually beginning to break a sweat (8)
I believe the answer is:
perspire
'sweat' is the definition.
(I know that sweat can be written as perspire)
'rips up 60% of the paper beforehand eventually beginning to break a' is the wordplay.
I cannot really see how this works, but
an anagram of 'rips' is 'rspi' which is located in the answer.
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is found in the answer.
A single letter 'e' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for perspire that I've seen before include "for every shoot" , "Sweat politely" , "Exude" , "Show effect of heat" , "Swelter" .)