2026 · Technical notes
How does layer count affect ballistic protection?
Buyers reading a soft armor spec sheet usually ask two things first: how many layers, and what areal density. Here is how those two numbers relate to protection level, using our own SB160 and SB130 data.
More layers means more areal density, up to a tested level
A soft armor panel is built from stacked cross-plied UD layers. Each added layer raises the panel’s areal density (its weight per square meter), and a panel only reaches a given NIJ protection level once its areal density passes the threshold that level requires. For SB160, 23 to 24 layers reach just over 3.6 kg/m2, enough for NIJ 0101.04 Level IIIA against 9mm. Reaching NIJ 0101.06 Level IIIA against .44 Magnum takes more: 31 to 32 layers, just over 4.9 kg/m2.
Why our own layer counts have dropped over time
The layer count needed for the same protection level against .44 Magnum has fallen as our fiber and weave quality improved. For SB160: 38 layers in 2007, down to 30 layers by 2019. For SB130: 46 layers in 2007, down to 40 layers by 2015. Fewer layers at the same protection level means a lighter, more flexible panel for the wearer.
What this means when you compare two suppliers’ spec sheets
Layer count on its own does not tell you much unless it is paired with the areal density and the exact threat and standard it was tested against. Two fabrics claiming the same layer count can differ in protection level if their areal density per layer is different. When you compare fabric, ask for all three numbers together: layers, areal density, and the specific standard and threat tested.
Full layer count and areal density tables for SB130, SB160 and SB166-225 are on the Soft Armor UD Fabric product page.