[1] While some spider silks are composed of a single protein, those of most interest to Kraig are a composite of two or more spider silk proteins.
[2] Kraig has obtained certain exclusive rights to use numerous spider silk genetic sequences which are the subject of five US patents held by the University of Wyoming. The University of Wyoming is a leader in spider silk research, and the University of Wyoming Foundation is a Kraig shareholder.
[3] Measured by the energy required to break a continuous filament, expressed in joules per kilogram (J/kg). A .357 caliber bullet has approximately 925 joules of kinetic energy at impact.
[4] Tensile strength refers to the greatest longitudinal stress the spider silk can bear, measured by force over area in units of newtons per square meter. The measurement here is in millions of pascals.
[5] In grams per cubic centimeter of material.
[6] Multiple independent protein fermentation providers provided these cost estimates. These estimates reflect the cost for usable silk protein on a per kilogram basis. Others may report costs per kilogram of fermentation solution not usable silk protein.