The ruling on exchanging a Meter for two Meters of Garments
Question :
Is it permissible to trade garments by exchanging a meter for two meters or one article for two articles?
Answer:
It is permissible to trade some garments with others with equal trading or an increase in some over others. It makes no difference whether they are of one type or more, and it makes no difference if that is done up front or for delayed payment. This is because fabric is not from the kinds of things in which Riba is included.
Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 3 Page 360