Johnson Window Films Dealer Resource Center

JWF, Basic Process

Curing Time

It looks foggy.
Haziness in film

After installation, the film may have a "hazy" appearance as well as a few water pockets. Don't be alarmed. The film is going through a drying-out process known as curing. This is to be expected because the barrier nature of the film prevents you from removing 100% of the water/soap solution located underneath the film.

Complete dry-out should occur within a few weeks (see curing chart below), depending on the amount of sunlight, humidity and heat directed upon the window. Do not clean the film during this drying period. Once the film is dry, clean the surface with a lint-free cloth and a mild soap and water solution. (FYI, silicone film cleaners provide enhanced clarity and durability). Always avoid cleaning windows in direct sunlight.

Here's the Visual Quality Standard for Applied Window Film as adopted by the International Window Film Association in 1999. The standards are still in place today and provide a detailed analysis on window film curing time.

Installed film on flat glass surfaces is not expected to have the same level of visual quality as glass. The following criteria applies to the installed film only, and not to any defect inherent in the glass:

1) Installed film has a discrete time for full adhesion to occur. Installation utilizes
a detergent solution in the water to float the film onto the glass: the excess water is squeegeed out, but inevitably residual water will remain between the film and glass.
The time to achieve full adhesion is often referred to as "the adhesive cure time". Adhesion increases from a lower value during this time. Visual and adhesive cure time depends on the thickness of the film and the various metallic coating on the film. Typical visual cure times may be extended or shortened according to climatic conditions.

2) Inspection for optical quality is possible before full visual cure is attained. Table 1 below provides a guide for typical visual cure times. Please note that effects during cure, such as water bubbles, water distortion, and water haze are not to be regarded as defects.

Table 1: Typical Cure Times

Film thickness
in mils
Film thickness
in microns (µ)
Typical Cure
Time (days)
Up to 4
Up to 100
4 to 8
100 to 200
8 to 12
200 to 300

3) The glass with applied film shall be viewed at right angles to the glass from the
room side, at a distance of not less than 6 feet (2 meters). Viewing should be in natural daylight, not in direct sunlight, and shall assess the normal vision area with the exception of a 2-inch (50mm) wide band around the perimeter of the unit.

4) The installation shall be deemed acceptable if all of the following are unobtrusive (effects during visual cure should be disregarded): Dirt Particles, Hair and Fibers, Adhesive Gels, Fingerprints, Air Bubbles, Water Haze, Scores and Scratches, Film Distortion, Creases, Edge Lift, Nicks and Tears. Inspection may be made within 1 day of installation. Obtrusiveness of blemishes shall be judged by looking through the film installation, under lighting conditions described in 3.

5) The 2 inch (50mm) wide band around the perimeter shall be assessed by procedures similar to those in 3 and 4. A small number of particles are considered acceptable where poor frame conditions mitigates the high quality standards normally achieved.

6) Edge gaps will normally be 1/32 - 1/16 inch (1-4mm). This gap allows for the water used in the installation to be squeegeed out. This procedure ensures that film edges are not raised up by contact with the frame margin. Contact with the frame margin could lead to peeling of the film.

7) For thicker safety films, the edge gaps will normally be 1/32 - 1/16 inch (1-4mm),
with 1/32 - 1/8 inch (1-5mm) being acceptable for films of [7 mil (175)]. Combination solar control safety films also fall within this standard. An edge gap of up to 1/16 inch (2mm)
is recommended, especially for darker (tinted, metallized, tinted/metallized, and sputtered) films, to minimize the light line around the edge of the installed film.

8) Splicing of films is necessary when larger panels of glass are treated, where both length and width of the glass exceed the maximum width of film. The splice line is not a defect. This line should be straight and should be parallel to one edge of the frame margin. The two pieces of film may be butt jointed. The maximum gap at any point in the splice line should be 1/64 inch (1mm). Film may be overlapped, spliced or butt jointed.

9) Certain films with special high performance coating may have lengthened cure times. Consult the manufacturer for cure times of these films.

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