Thin bedcover Romeo brought in for model (5)
I believe the answer is:
sheer
'thin' is the definition.
(similar in meaning)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for sheer that I've seen before include "Very thin as in ladies' stockings" , "Simple" , "Completely" , "Very fine or vertical" , "Very fine like silk stockings" .)