Window tint

Window tint percentages: film and glass work together

Understand VLT, factory glass and why a film's advertised percentage does not always equal the final light transmission of the window.

By Motenza Custom WrapOctober 24, 20262 min read

The percentage usually refers to visible light transmission. It is not the percentage of heat blocked. The existing glass already affects light, so installing a film changes the combined system rather than replacing the glass's characteristics.

Read the number in the right direction

A film described as 70% VLT transmits more visible light than one described as 20%. That does not tell you everything about solar performance, reflectivity or color. Compare those properties separately using the product's technical data.

Account for the original glass

As a simplified illustration, 80% glass combined with 50% film gives approximately 40% transmission when the fractions are multiplied. Real installed results should be measured; product naming and test glass can differ. This example explains the interaction and is not a certification of any installation.

Window film installation on the open door of a silver Mercedes-Benz sedan

Look through samples, not only at them

A shade can appear different against a dark interior or beside factory privacy glass. Assess outward visibility as well as exterior appearance. Consider nighttime driving and the driver's needs before selecting a finish. Phone screenshots are not reliable measurements of tint darkness.

Confirm the specific application

Discuss each window separately and check the requirements that apply to the vehicle and glazing. Do not infer legal compliance from a film label or this arithmetic example. Ask Motenza to document the selected film and measured installed result as part of the project discussion.