Thin sheet up to storing data (7)
I believe the answer is:
tinfoil
'thin sheet' is the definition.
'tinfoil' can be an answer for 'sheet' (tinfoil is a kind of sheet). I am unsure of the 'thin' bit.
'up to storing data' is the wordplay.
'up to' becomes 'til' (I've seen this in another clue).
'storing' means one lot of letters goes inside another.
'data' becomes 'info' (information).
'til' going around 'info' is 'TINFOIL'.
Can you help me to learn more?
(Other definitions for tinfoil that I've seen before include "Fine metal" , "Thin metal sheet for wrapping food etc" , "Food wrapper" , "up to wrapping up dope" , "what can protect food" .)