Koala Paper Waterproof Screen Printing Film Guide

When it comes to achieving sharp, high-quality prints in the screen printing industry, one material plays a crucial behind-the-scenes role—screen printing film. Often overlooked by end customers, this transparent sheet is vital to producing crisp stencils, precise color separations, and consistent print quality across a wide range of materials.

In this article, we’ll break down what screen printing film is, why the waterproof type is superior, how it’s used, and how to choose the right one for your printing needs—with real product insights from Koala Paper, a trusted manufacturer in the field.

What Is Screen Printing Film?

Screen printing film is a transparent or translucent polyester (PET) sheet coated with a specialized ink-receptive layer. It is used to transfer artwork or text onto a screen during the screen printing process. When exposed to light, the film allows light to pass through the transparent areas while blocking light in the printed black areas, creating a stencil on the emulsion-coated screen.

This film is essential in the pre-press stage of screen printing and is used across various applications—from T-shirts and posters to circuit boards and promotional items.

✅ Koala Paper’s waterproof inkjet films are made with premium PET and a high-density coating, specifically designed for precise stencil creation and UV-blocking performance.

Waterproof vs. Non-Waterproof Film: What’s the Difference?

One of the most important distinctions to make when shopping for screen printing film is whether it’s waterproof. While both waterproof and non-waterproof films can serve the same basic function, waterproof versions offer several advantages:

✅ Smudge Resistance

Waterproof inkjet films are designed to prevent ink bleeding or smudging, especially in humid or fast-paced working environments.

✅ High-Density Black Output

Waterproof films tend to absorb more pigment ink, resulting in deeper and more opaque blacks. This helps block UV light effectively during exposure, ensuring sharper stencils.

Koala Paper’s films are optimized for pigment inks, producing solid black lines ideal for sharp, high-resolution stencils.

✅ Better Dimensional Stability

Thanks to the waterproof coating, the film remains flat and stable, even with heavy ink coverage or under heat. This ensures accurate registration between colors in multi-layer prints.

✅ Compatibility with Pigment and Dye Ink

Many waterproof screen printing films are specially coated to accept both dye-based and pigment-based inks, increasing their compatibility with a range of inkjet printers.

How to Use Screen Printing Film

Using screen printing film in a print shop is relatively straightforward. Here’s a step-by-step overview:

Create Your Artwork

Use vector-based software like Adobe Illustrator or raster software like Photoshop to prepare your design. Make sure the artwork is set to pure black (100% K).

Print the Film

Load the waterproof screen printing film into your inkjet printer. For best results, use a printer that supports pigment ink and high-density black output. Print on the coated (matte) side of the film.

Koala Paper recommends using Epson or Canon pigment-based printers with its screen printing films for optimal results.

Dry and Inspect

Allow the ink to dry completely before handling. Check the film for opacity and clean edges—these will impact the exposure quality.

Expose the Screen

Place the printed film on top of a screen coated with emulsion and expose it to UV light. The black areas will block the light, and the clear areas will allow it to pass through.

Wash and Dry

After exposure, wash out the screen using water. The areas that were blocked by the black ink will wash away, creating a stencil for your print job.

Choosing the Right Screen Printing Film

With many options on the market, selecting the right film can be overwhelming. Here are a few things to consider:

📏 Film Thickness

Standard waterproof inkjet films are around 100 microns thick. Thicker films tend to offer better flatness and fewer registration issues.

🖨️ Printer Compatibility

Make sure the film is compatible with your printer type—most commonly, dye or pigment inkjet printers. Check for quick-drying coatings to prevent ink smears.

🌦️ Environmental Resistance

If your shop experiences high humidity or temperature fluctuations, a waterproof screen printing film will offer more stability than non-coated versions.

🌱 Eco-Friendly Options

Some manufacturers now offer eco-conscious PET films made with recycled materials or lower-emission coatings.

Koala Paper is continuously developing sustainable PET substrates and environmentally friendly coatings to meet growing demand for green printing solutions.

Final Thoughts

Whether you're producing T-shirts, signs, or promotional goods, screen printing film is a foundational material that directly affects print quality. Investing in a high-quality waterproof screen printing film ensures clean, smudge-free prints with excellent UV blocking and dimensional stability.

For reliable and professional results, Koala Paper offers waterproof screen printing films that combine premium PET base, fast-drying coatings, and excellent compatibility with various inkjet printers.

It’s a small component, but it makes a big difference.