Abstract FIBERGLASS FILAMENT UNWOUND FROM A SERIES OF SPOOLS IS IMPREGNATED WITH A RESIN MATRIX AND PASSED THROUGH A PAIR OF ROLLERS OR SIZING BUSHING FOR REMOVING THE EXCESS RESIN AND AIR THEREFROM. THE RESIN IMPREGNATED FIBER GLASS IS THEN ENVELOPELY ENCLOSED WITHIN A SHEET OF UNIDIRECTIONALLY ORIENTED PLASTIC FILM, LATTER BEING SEALED ALONG ITS UPPER LONGITUDINAL MARGIN BY MEANS OF AN ULTRASONIC WELD OR HEAT WELD. THE FILM ENCLOSED COMPOSITE MAY THEN BE HEATED TO SHRINK THE FILM. THE TEMPERATURE SHOULD BE SUFFICIENTLY LOW TO HAVE NO CURING EFFECT ON THE RESIN LEAVING IT IN THE UNCURED OR SO-CALLED "A-STAGE." FOR SOME SYSTEMS IT IS DESIRABLE TO ADVANCE THE RESIN TO A SEMI-CURED OR SO-CALLED "B-STAGE." THE FILM ENCLOSED COMPOSITE MAY THEN BE WOUND UPON SUITABLE REELS AND STORED FOR FURTHER USE.