Definition

Glass style refers to the standardized fiberglass cloth weave patterns used in PCB laminates and prepregs. Common styles include 1080 (light, thin), 2116 (medium, most common), and 7628 (heavy, thick). The number indicates weave density and yarn configuration. Glass style affects dielectric thickness, resin content, and Dk variation (weave pattern causes periodic Dk changes that can affect high-speed signals). Spread glass technology flattens fibers for more uniform Dk. Multiple plies of different glass styles can achieve target thickness.