Times article about a rare material (6)
I believe the answer is:
tartan
'material' is the definition.
(I know that tartan is a type of material)
'times article about a rare' is the wordplay.
'times' becomes 'tt' (two abbreviations for time).
'article' becomes 'an' (indefinite article).
'about' means one lot of letters goes inside another.
'rare' becomes 'r' (listed by Oxford Dictionary of Abbreviations).
'tt'+'an'='ttan'
'a'+'r'='ar'
'ttan' enclosing 'ar' is 'TARTAN'.
(Other definitions for tartan that I've seen before include "Scottish costume design" , "Pattern of the Scottish clans" , "Scots patterned cloth" , "dress?" , "Distinctive pattern of Highland clan as seen in kilt" .)