Chemically treated glass fibers of the present invention provide good processing properties in reinforcing thermosetting polymers while resulting in fiber reinforced thermosetting materials having good strength properties. The chemically treated glass fibers have a dried residue of an aqueous chemical treating composition having: two film forming polymers, at least an acryloxy alkyl trialkoxysilane, a fiber lubricant and polyester curing agent and water. One film forming polymer is a polyvinylacetate copolymer having a low solubility in acetone and the other film forming polymer is unsaturated, curable, essentially linear polyester polymer. The fiber lubricant is a nonionic polyethylene-containing polymer or a cationic lubricant like polyalkylene polyamine polyamino amide, and partially amidated polyalkylenimines and mixtures thereof present in an effective lubricating amount. The nonionic lubricant may be used and the cationic lubricant is used in conjunction with a fuzz reducing agent such as silylated polyazamide. Additional components which may be present include: an amino organofunctional silane coupling agent, and a polyoxyethylene polymer having a molecular weight in the range of 100,000 to 5 million. The dried residue is present on the fibers in the strand in an amount in the range of around 1.5 to 3 percent LOI. Also, the dried strands have a post treatment with an antistatic agent before the strands are utilized as reinforcement for thermosetting materials.