Spare bit of paper to wrap small portions of chips up (6)
I believe the answer is:
offcut
'spare bit' is the definition.
'of paper to wrap small portions of chips up' is the wordplay.
'paper' becomes 'ft' (newspaper the FT, Financial Times).
'to wrap' is an insertion indicator.
'small portions of' says to take the initial letters.
The first letters of 'chips up' is 'cu'.
'ft' going around 'cu' is 'fcut'.
'of'+'fcut'='OFFCUT'
(Other definitions for offcut that I've seen before include "bit of stick?" , "Remnant of material" , "Remnant for other uses" , "Waste piece" , "Small bit of some material" .)