Instruction to make dirty photo? (9)
I believe the answer is:
blueprint
'instruction' is the definition.
'dirty photo?' is the wordplay.
'dirty' becomes 'blue' (blue can mean pornographic).
'photo?' becomes 'print' (as in a print of a photograph).
'blue'+'print'='BLUEPRINT'
'to make' acts as a link.
(Other definitions for blueprint that I've seen before include "Original plan influencing subsequent decisions" , "Prototype" , "Technical drawing" , "Design or guide for making something" , "sketch" .)