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Windshield Sun Strips (Visor Strips) Explained
A sun strip, also called a visor strip or eyebrow, is a band of window film across the top of the windshield. It is the one piece of aftermarket tint South Carolina allows on the windshield, and it is aimed at one specific problem: sun that sits just above your line of sight and slips past the visor.
It is a simple product with a precise legal boundary. This guide explains what the AS1 line is and how to find it, what the statute does and does not say about the strip, how much a strip can realistically help with glare, and the questions worth asking before one goes on.
The short answer
A windshield sun strip is a band of nonreflective film along the top of the windshield that cuts glare from a high or low sun. In South Carolina it may only run along the top and may not extend below the AS1 line marked on the glass; if no AS1 line is visible, no film may go on the windshield at all. It cannot be red, yellow or amber, and the statute sets no separate darkness number for the strip.
Key points
- South Carolina allows windshield film only along the top of the glass, above the AS1 line, and none if the line is not visible.
- The AS1 marking comes from the federal glazing standard and marks the part of the windshield that meets the light-transmittance test.
- The strip must be nonreflective and may not be red, yellow or amber; the statute gives no minimum light transmission for it.
- A sun strip helps when the sun sits near the top of your view; it does nothing for sun straight ahead at eye level.
- Clear heat-rejecting film over the whole windshield is not carved out of the AS1 rule in South Carolina's text.
The basics
What a Sun Strip Is and What It Is For
A sun strip is a piece of tint film cut to follow the top edge of the windshield and finished in a straight or gently curved line a few inches down. It goes on the inside of the glass, like side window film. Many are a dark charcoal so the band reads as a deliberate part of the car, often blending with the black ceramic border the factory prints around the glass.
Its job is glare. When you drive toward a rising or setting sun, the light often sits in the gap between the top of the windshield and the bottom of the visor, or it shifts as the road curves and the visor ends up pointing the wrong way. A strip shades that top band all the time, without anyone flipping a visor down.
The line
What the AS1 Line Is
Every piece of automotive safety glass carries a small printed marking, usually in a corner, with the glass maker's information and a code for the type of glazing. The federal glazing standard, FMVSS No. 205, adopts the ANSI/SAE Z26.1 code for these markings. On a windshield you will often find the letters AS1 with an arrow beside them, sometimes printed at both edges of the glass.
The arrow is the key part. Under the federal standard, it points to the portion of the glass that complies with the light-transmittance test, and its base sits against a horizontal line. That line is what tint people mean by the AS1 line. Above it, the factory may add a shaded band; below it, the glass has to meet the light requirement. South Carolina's statute defines AS1 by reference to the same federal glazing rule.
Check the upper corners
Look along the left and right edges of the windshield toward the top, near the black border. Some windshields print AS1 with a small arrow at the height of the line.
Read the glass marking
The main marking block, with the glass maker's name and codes, is usually in a corner. Read it for the AS1 code and an arrow.
Follow the arrow to the line
The arrow's base sits on a short horizontal line. A sun strip must stop at or above that height across the glass.
No marking, no film
If you cannot find a visible AS1 line, South Carolina's statute says no sunscreening device may be applied to the windshield.
The law
What South Carolina's Statute Says About Strips
Subsection (B) of S.C. Code § 56-5-5015 covers windshields in three sentences. A sunscreening device must be nonreflective and may not be red, yellow or amber. It may be used only along the top of the windshield and may not extend downward beyond the AS1 line. If the AS1 line is not visible, no sunscreening device may be applied to the windshield.
Notice what is not there: a light-transmission percentage for the strip. The 27% combined rule in the statute applies to the side windows and the rear-most window. For the windshield, the limits are position (above AS1), finish (nonreflective) and color. The statute also requires a certificate of compliance attached to the inside lower right corner of each window containing after-factory film, and its text does not exclude the windshield, so ask your installer how they handle it.
Factory bands
Factory Shade Bands Are a Different Thing
Some windshields leave the factory with a tinted band across the top, built into the glass or its laminate. The federal standard regulates where these shade bands can go: the lower edge must follow either an SAE recommended practice or a plane angled 7 degrees up from a reference point. That is the automaker's job, not something an owner adds.
South Carolina's light-transmission rules only apply once after-factory film has been added, so a factory shade band is not a tint violation. If your windshield already has one, an extra film strip may add little, and the AS1 line may sit right at the bottom of the factory band.
Expectations
What a Sun Strip Can and Cannot Do
- Helps with
- Sun that sits near the top of your view: early morning and late afternoon light on long east-west stretches, and sun that slips past the edge of the visor. It also adds some shade to the top of the cabin.
- Does not help with
- Sun straight ahead at eye level, which on I-85 or US-76 at sunrise and sunset is often the worst of it. Below the AS1 line is legally off-limits, so a strip cannot reach where your eyes are. Good sunglasses and a clean windshield do more there. Glare and driving into the sun
- Does not replace
- Your visor, or side window film. Most sun on your arm and face comes through the side glass, which a windshield strip does nothing for.
Full windshield
What About Clear Film on the Whole Windshield?
Film makers sell nearly clear ceramic films that reject heat without visibly darkening the glass, and LLumar notes that clear tint can be used on windshields while state laws regulate darkness. South Carolina's statute, though, does not frame the windshield rule around darkness. It says a sunscreening device may be used only along the top and may not extend below the AS1 line, and it defines sunscreening device as a film designed to be used with safety glass to reduce the effects of the sun.
On its plain text, that does not leave a carve-out for clear heat-rejecting film below the line. If you are considering it, treat it as not permitted in South Carolina unless SCDPS or a lawyer tells you otherwise. A glass coating is a different product: it goes on the outside of the windshield to help water bead and clear, and does not tint or block light.
Before you buy
Questions to Ask Before a Strip Goes On
- Where is the AS1 line on my windshield, and will the strip stop at or above it all the way across?
- Is the film nonreflective, and is it a neutral charcoal rather than a colored film?
- Does my car have a camera or sensor mounted behind the windshield near the mirror, and how will the strip be cut around it?
- Will it look right with my factory black border or shade band?
- How is the certificate of compliance handled for the windshield?
- Is the same film being used on my side windows, so the tones match?
Ask about a sun strip with your tint job
Tell us what you drive and what kind of glare bothers you. We will look at where your AS1 line sits and talk through whether a strip helps, alongside LLumar film for your side windows.
Common questions
How far down can a windshield sun strip go in South Carolina?
Only to the AS1 line marked on your windshield glass, and no farther. South Carolina's statute says windshield film may be used only along the top and may not extend downward beyond the AS1 line. If that line is not visible on your glass, no film may be applied to the windshield.
How dark can a sun strip be?
South Carolina's statute does not set a light-transmission percentage for the windshield strip. It requires the film to be nonreflective and not red, yellow or amber, and limits where it goes. Many drivers pick a dark charcoal so the band blends with the factory black border.
Can a sun strip have lettering or a colored band?
The statute bans red, yellow and amber film on the windshield and requires it to be nonreflective, so colored or mirror-finish banners are out. Anything that adds reflectivity or one of those colors would not meet the rule. Stick to a neutral, nonreflective film.
Will a sun strip interfere with my car's driver-assist camera?
It can if film covers the camera's view. Many newer cars mount a camera behind the windshield near the mirror, inside a housing. A careful installer cuts the strip around that area. If your owner's manual says to keep the area clear, follow it.
Is a sun strip worth it if I already have sunglasses?
They solve different problems. Sunglasses cut overall brightness and glare from the road ahead. A strip shades sun sitting near the top of the windshield, above where sunglasses help most. If you face low sun on a daily commute, the two work well together.
Keep reading
Sources
- S.C. Code Ann. § 56-5-5015, South Carolina Legislature (https://www.scstatehouse.gov/code/t56c005.php), accessed October 2026
- 49 CFR 571.205, Standard No. 205, Glazing materials (S5.1.3 AS markings, S5.3 shade bands), Legal Information Institute, Cornell Law School (https://www.law.cornell.edu/cfr/text/49/571.205), accessed October 2026
- Ford Motor Company; Grant of Application for Decision of Inconsequential Noncompliance, 60 FR 31345, NHTSA via Federal Register (https://www.govinfo.gov/content/pkg/FR-1995-06-14/html/95-14488.htm), accessed October 2026
- Automotive Window Tint Frequently Asked Questions, LLumar / Eastman Performance Films (https://llumar.com/en/resources/automotive-window-tint-frequently-asked-questions/), accessed October 2026
- Clear Performance Film, LLumar / Eastman Performance Films (https://llumar.com/en/tint/clear/), accessed October 2026
Prices on this page are The Auto Show’s published starting prices. Film ratings and warranty terms come from the manufacturer. This guide explains South Carolina law in plain words; it is not legal advice.