  A study has been perfomed on the superconducting critical current density
J_{c} flowing across low angle grain boundaries in epitaxial thin films of
YBa{2}Cu{3}O{7-d} (YBCO). The materials studied were dual grain boundary rings
deposited on SrTiO{3} and containing 2, 3, 5 and 7 degree tilt boundaries. The
current density in self-field was determined by magnetometric methods at
temperatures from 5 K to T_c. We conclude that at the higher temperatures of
coated conductor applications, there is limited potential for improving J_{c}
by reducing the grain boundary angle below about 3 degrees.
