A method of making a nonwoven fibrous mat that retains good strength and recovery after scoring and folding, properties making the mat useful in making collapsible ceiling tile. The mat comprises a majority of glass fibers and a minority of polymer fibers, the fibers being bound together with up to 35 wt. percent of a polyacrylic acid and polyol polymer binder based on the dry weight of the mat. The mat can be cured to “B stage”, thermoformed into the desired shape and then heated further to complete the cure of the binder.