The purpose of this work is to screen candidate materials for use in the iodine laser which operates at 1.315 μm. Most of the results presented here are the effective optical absorption, β^eff, measured by laser rate calorimetry using a Quantronix Nd:YAG laser modified to operate at 1.319 μm. Spectral transmission scans using the Beckman UV 5270 and Perkin-Elmer 180 spectrophotometers are presented on the less common materials. In the beginning we measured β on materials obtained for CO², CO and HF-DF laser studies. These included NaCl, KCl, LiF, CaF², SrF², Al²O³ (sapphire), ZnSe, Si and GGG (Gd³Ga⁵O¹²). At 1.3 μm a number of oxides which were too absorbing to use at the longer wavelengths can be considered. We present results on a variety of commercially available fused silicas, SiO². Additional results on BaF², Raytran ZnS, spinels (xMgO·Al²O³), MgO, Barr and Stroud BS37A and BS39B calcium aluminate glasses, CORTRAN 9753 and 9754 glasses, ZBT glass, undoped YLF (LiYF⁴) and As²S³ will be presented.