The present invention features improved in vitro RNA display libraries to allow reliable expression and selection of scFv antibody molecules from expression libraries. The scFv antibody libraries of the invention contain an optimized, shortened inter-domain linker that improves expression scFv antibody expression. The scFv antibody libraries also include short nucleic acid barcodes that allow for identification of individual library clones, libraries or subsets thereof. Primers for generating, amplifying and spectratyping the scFv antibody libraries of the invention are also provided.