substantially cure the composition and then heated for a second time at a higher temperature and or for a longer period of time to effect curing such a procedure referred to as u201c b staging u201d may be used to provide binder treated nonwoven for example in roll form which may at a later stage be cured with or without forming or molding into a particular configuration concurrent with the curing process the heat resistant nonwovens may be used for applications such as for example insulation batts or rolls as reinforcing mat for roofing or flooring applications as roving as microglass based substrate for printed circuit boards or battery separators as filter stock as tape stock as tape board for office partitions in duct liners or duct board and as reinforcement scrim in cementitious and non cementitious coatings for masonry due to the good hydrolytic stability of the binders and good humid aging performance products prepared using the methods disclosed herein can be used under varying environmental conditions measurement of rigidity generally involves preparing a specimen of fiberglass product for testing placing the specimen in contact with water and determining the water resistance of the specimen the water resistance can be determined by either qualitative or quantitative techniques measurement of rigidity can be used to evaluate.