Perforated Window Film: Advertising on Shop Windows and Rear Windows, with a View Out from Inside

A shop window is advertising space the business is paying for anyway. It is also the trickiest. Cover it completely and the display is gone and the room behind it goes dark. Leave it empty and the brand appears nowhere.

Perforated window film sits exactly in between: passers-by see a full-coverage design from outside, while from inside the view out is largely preserved. The effect does come with one condition, though, and it depends on the light.

The information here comes from the application guidelines of several brand-name manufacturers, as of September 2026. If the data sheet for your film says something different, the data sheet applies.

What is perforated window film?

Perforated window film is a self-adhesive, perforated film, usually with a white, printable front and a black back; other backs are available for special cases. In between sits a regular grid of holes. The white side is printed. In the trade, the same material is also sold as "perforated film", "one-way vision film" or "see-through film".

The hole diameter is usually 1.5 mm, and there are versions with 1.0 mm for finer designs. Common perforation ratios are 50/50, 60/40, 70/30 and 80/20; for retail shop windows, manufacturers name 70/30 as the usual choice and 60/40 as the all-rounder.

One thing causes confusion: some manufacturers state the share of printable area in the data sheet, others the open share. So the same figure can stand for two different things.

Why you can see out from inside but not in from outside

The light takes care of that. From inside, the eye looks through the holes into the brighter side, and the white surface around them fades into the background. From outside, the printed design is in the light, with the black back behind the holes. The perforation disappears and the design looks solid.

The larger the open share, the more light and view remain inside, and the weaker the image looks outside. The smaller it is, the stronger the design and the darker the room behind it.

Now the limitation that matters before you order: the effect only works as long as it is brighter outside than inside. In the evening, when the lights are on in the shop and the street is dark, it reverses. The design looks washed out and people can see in from outside. Perforated film is therefore not a privacy screen. If you want the glass to be opaque, frosted or etched-glass film is the better choice.

Where perforated film works and where it doesn't

Shop windows, glass doors, glass facades

Manufacturers list shop windows and building glazing, glass doors and glass walls as typical applications. That is where it pays off most: large glass surfaces that work as advertising space without turning the room behind them into a bunker. How such a surface needs to be designed so that it can be read from a distance is covered in Stickers you can't overlook.

Rear windows and vehicle glazing

Rear and side windows of vehicles are the second classic application. Rear windows, however, are usually heated. Whether a film may go on them is stated in the data sheet; some products rule out windows with heating elements, defrosters or wiper areas. We check this on the specific vehicle before you order.

In Austria, the following applies:

• Under § 7a (3) KDV 1967, the Austrian Motor Vehicles Implementing Regulation, perforated films may be applied to side windows from the second row of seats backwards, to the rear window and to roof windows.
• § 7a (2) KDV 1967 rules out applying film to the windscreen after the fact.
• Under § 7a (4) KDV 1967, a vehicle with perforated film on the rear window or the rear side windows must have two main rear-view mirrors of class III or II in accordance with Directive 2003/97/EC.
• Window films are parts that require approval; a type approval granted in an EU member state is sufficient. Under § 7a (1) KDV 1967, the approval mark must remain visible once the film is applied.

The version quoted is the one in force in September 2026. This is guidance, not legal advice: for vehicles without a second row of seats, such as panel vans, the authority or the vehicle inspection centre decides in case of doubt. Make sure the film used carries an approval mark and that it stays visible. The film manufacturers, too, refer to national regulations and to the responsibility of the user. More on this on our vehicle graphics page.

Where we advise against it or check first

Manufacturers do not recommend the film on coated glass, meaning anti-reflective, self-cleaning or scratch-resistant glass: the coating can be damaged when the film is removed. Your glazier or window fitter will know which glass is installed.

A second point is heat: large, dark or highly opaque designs on glass exposed to the sun increase heat absorption, and with insulating glass this can lead to thermal stress and even glass breakage. So check with your glazier beforehand.

Laminate, durability and cleaning

"Perforated film always has to be laminated" is a persistent claim, but it is not true: it depends on the product. Some manufacturers require a protective laminate for outdoor use, because otherwise moisture collects in the perforation; others do not consider it necessary for typical applications. For vehicle graphics, the application guidelines also recommend an edge sealing tape.

There is no universal figure in years, and the data sheets we checked are far apart: one manufacturer states four years for the unprinted film on vertical glass in a Central European climate, another three to ten years depending on the product. What counts is the figure for the exact film being applied, so ask for it when you enquire.

When cleaning, the start matters: wait at least 24 hours after installation, because the adhesive needs time to reach its final bond; the exact waiting time is in the data sheet. After that, mild soapy water and a soft cloth, and a soft brush will get dirt out of the holes. From then on, for care: no solvents, including no alcohol and no ammonia. No pressure washer, nothing abrasive. For vehicles, that means no brush car wash; hand wash, keeping your distance from the nozzle.

Applying perforated film: what depends on the perforation

The biggest difference from an ordinary sticker: the application guidelines we checked all, without exception, specify dry application for perforated film. Wet application is out, because water stays in the holes and spoils the view through.

The surface has to be clean and free of grease, or the film ends up sticking to the cleaning agent instead of the glass. Clean thoroughly, finishing with soapy water, then rinse and let it dry. Only apply above the minimum temperature in the data sheet, often from +10 °C, measured on both the film and the surface. And the film ends on the glass, not over seals or glass edges.

On heated rear windows and coated glass, do not peel the film off yourself: heating wires, antenna conductors and coatings can come away with it. In that case, ask us first. Otherwise: to remove it, lift the film at an upper corner and peel it off under tension. Whether heat helps or harms is stated in the data sheet. If you don't want to apply it yourself, our sign-making team will handle the installation. An overview of films for glass surfaces: Foil technology.

Print files, design and size

Measure the window. What you need is the visible glass size up to the frame or glazing bead, not the outer dimensions of the frame. For wide shop windows, the print width decides how many panels are needed.

Keep the design bold. The perforation takes away part of the area from every printed image. Large shapes, clear edges and high contrast hold up; hairlines and small text suffer. For fine designs there is the smaller perforation.

We look over your print files before printing, and the file check costs nothing. It is purely a technical check: format, resolution, bleed, cut line, white layer and print direction, inside or outside. We do not check content or spelling. The side it is stuck on is what matters. If the design goes on the inside of the glass, supply the file the right way round and state "inside". We do the mirroring. Whether a perforated film is intended for application on the inside is stated in the data sheet.

Perforated film or cut vinyl lettering?

Not every window needs perforated film. Cut vinyl lettering puts your name, logo and opening hours on the glass and leaves the rest of the window as it is. It costs nothing in terms of view, but it cannot carry an image. If you want a photo or a continuous area of colour, there is no way around perforation.

There are two other routes: clear film with white ink if the design needs to look opaque, and frosted or etched-glass film if privacy is the point. In the end, two questions count: how much area should the design take up, and how much view needs to remain?

When the promotional panel is meant to cover the whole front

The case is made up, but it sums up typical enquiries. A shop with a large window front wants a promotional panel across the whole pane. Inside it should still stay bright, and people should still be able to look in.

Full-coverage film is ruled out, and cut lettering cannot carry the design. That leaves perforated window film. What tips the case is the lighting: in the evening the lights are on inside, and the panel looks different from how it looks in the morning. So it is not stretched across the whole front, but placed where it is read from the street during the day. The glass construction was also clarified beforehand; with insulating glass, the glazier has a say.

With perforated film, light comes first

Perforated film is not sold on the holes, it is sold on the light. That has been our approach since the company was founded in 2017, and our founder, with more than 30 years in the trade, has worked this way for longer.

If you only look at the perforation ratio, you are answering the wrong question. What matters is how bright it is on which side of the glass, and when the panel needs to work. That can be planned, but only before you order.

Conclusion: weighing view-through against impact

With this material, advertising impact outside and view through inside pull directly against each other. If you weigh them up beforehand, you get both in a workable balance. Clarify three points before you order:

• Light: when should the panel work, and how bright is it behind it in the evening?
• Glass: insulating glass, coated, heated? What is the visible glass size?
• Product: what does the data sheet say about laminate, durability and application on the inside?

Tell us which window it is and where the design should be read from: Contact. We plan perforated film with you; standard custom stickers are ordered through our shop koeck-print.at.

Frequently asked questions

Can I still see out through perforated window film?

Yes. From inside, that is from the black back, the view out is largely preserved. How much depends on the open share: the larger it is, the more light and view remain inside, and the weaker the design looks outside. The effect only works as long as it is brighter outside than inside.

Does perforated window film need a protective laminate?

Not always; it depends on the product. According to their data sheets, some manufacturers require a protective laminate for outdoor use, because otherwise moisture collects in the perforation. Others do not consider it necessary for typical applications. For vehicle graphics, the application guidelines also recommend an edge sealing tape. The data sheet of the specific film is what counts.

Can perforated film be applied wet?

No. The application guidelines we checked all, without exception, specify dry application, because water stays in the holes and spoils the view through. The glass must be clean and degreased beforehand, and the film is only applied above the minimum temperature in the data sheet, often from +10 °C.