  The recently completed Forward GEM Tracker (FGT) of the STAR experiment at
RHIC took advantage of commercially produced GEM foils based on double-mask
chemical etching techniques. With future experiments proposing detectors that
utilize very large-area GEM foils, there is a need for commercially available
GEM foils. Double-mask etching techniques pose a clear limitation in the
maximum size. In contrast, single-mask techniques developed at CERN would allow
one to overcome those limitations. We report on results obtained using 10
$\times$ 10 cm$^2$ and 40$\times$40 cm$^2$ GEM foils produced by Tech-Etch Inc.
of Plymouth, MA, USA using single-mask techniques and thus the beginning for
large GEM foil production on a commercial basis. A quality assurance procedure
has been established through electrical and optical analyses via leakage
current measurements and an automated high-resolution CCD scanner. The
Tech-Etch foils show excellent electrical properties with leakage currents
typically measured below 1 nA. The geometrical properties of the Tech-Etch
single-mask foils were found to be consistent with one another, and were in
line with geometrical specifications from previously measured double-mask
foils. The single-mask foils displayed good inner and outer hole diameter
uniformities over the entire active area.
