The most common and most likely answer to this crossword clue is the 6 letter word PLAIDS
P
L
A
I
D
S
Buddy explains!
The straight part
We know that "Materials" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case materials = plaids.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PLAIDS mean?
PLAIDS noun- A type of twilled woollen cloth, often with a tartan or chequered pattern.
- A length of such material used as a piece of clothing, formerly worn in the Scottish Highlands and other parts of northern Britain and remaining as an item of ceremonial dress worn by members of Scottish pipe bands.
- The typical chequered pattern of a plaid; tartan.