When sourcing glass frit, the most critical technical factor is the Coefficient of Thermal Expansion (CTE), which must match the substrate (metal, ceramic, or glass) to prevent cracking. You should also specify the Particle Size Distribution (D50/D90), as this affects the melting rate and coating uniformity. For specialized uses, verify the Softening Point (Ts) and Transformation Temperature (Tg) to ensure compatibility with your firing kilns. High-quality suppliers on Made-in-China.com typically provide a Certificate of Analysis (COA) detailing the chemical composition, including silica, boron, and alkali metal content.