Crisp packet's final design showing text (6)
I believe the answer is:
script
'text' is the definition.
(I know that script is a text)
'crisp packet's final design' is the wordplay.
'final' says to take the final letters.
'design' is an anagram indicator.
The last letter of 'packet' is 't'.
'crisp'+'t'='crispt'
'crispt' with letters rearranged gives 'SCRIPT'.
'showing' is the link.
(Other definitions for script that I've seen before include "Orginal document" , "Write" , "Handwriting, play text" , "Written version of a play" , "Calligraphy" .)