"When pressed, creases," I put in, "will vanish" (8)
I believe the answer is:
disperse
'vanish' is the definition.
(thesaurus)
'when pressed creases i put in' is the wordplay.
I cannot quite see how this works, but
'i' is within the answer.
an anagram of 'pressed' is 'dsperse' which is within the left over letters.
No letters remain.
This explanation may well be incorrect...
'will' is the link.
Can you help me to learn more?
(Other definitions for disperse that I've seen before include "Presides so as to scatter" , "Scatter, dispel" , "Thin out and disappear" , "Scatter, break up" , "Broadcast" .)