One of the most common ways to make graphics on clothes, signs, and promotional products is through screen printing. It’s known for producing bold, vibrant, and long-lasting designs on various surfaces like fabric, paper, glass, plastic, or metal. But one question beginners often ask is:
Which film is used in screen printing, and why is it so important?
The film in screen printing plays a crucial role—it’s the medium that carries the design and helps create the stencil on the screen. Without the right type of film, your designs won’t transfer correctly, leading to poor-quality prints. In this guide, we’ll cover everything you need to know about films in screen printing, including the types, how they’re used, and tips for choosing the best one for your projects.
Introduction to film is used in screen printing
Film is used in Screen printing has been around for centuries, but the process has remained remarkably consistent: a stencil (or screen) is used to transfer ink onto a surface. One of the most critical parts of this process is making the stencil, and that’s where film comes in.
A film positive is a clear sheet with your design printed in solid black on it. During screen exposure, this film blocks UV light from hardening the emulsion in certain areas, leaving open spaces where ink will later pass through. Without the right kind of film, your stencil may end up blurry, incomplete, or poorly aligned. That’s why it’s important to understand which film is best for screen printing.
What Is Screen Printing Film?
Film is used in Screen printing, film is a transparent material—usually polyester—that holds your artwork for the exposure process. The design is printed in solid, opaque black ink so that when light passes through the transparency, it creates a mask.
- Film Positives: These are the most common type. They display the design in black on a clear sheet.
- Transparency Sheets: Similar to overhead projector transparencies but specifically designed for printing high-density black ink.
The purpose of the film is simple: it tells the screen where to let light through and where to block it.
Why Is Film Used in Screen Printing?
Film is essential for three main reasons:
- Stencil Creation – When the coated screen is exposed to UV light, the clear areas of the film let light pass through, hardening the emulsion. The black parts keep light from getting to the emulsion, which makes some parts soft so they may be washed away. This becomes your stencil.
- Blocking UV Light – The darker and denser the black areas on the film, the better the stencil quality. If the black isn’t opaque enough, light will seep through, leading to fuzzy or incomplete designs.
- Sharp and Accurate Designs – A good-quality film ensures that even fine details and halftones are transferred properly onto the screen.
Types of Screen Printing Film
There isn’t just one kind of film—several types are used depending on your setup, budget, and printing needs.
1. Inkjet Film Positives
- Made for use with inkjet printers
- Coated for better ink absorption
- Produce dense, dark blacks suitable for exposure
- Most common in small businesses and DIY setups
2. Laser Film Positives
- Designed for laser printers
- Toner-based, not ink-based
- Work well for bold designs but may struggle with fine details
3. Vellum Paper
- Thin, semi-transparent paper used historically in screen printing
- Much cheaper but less reliable than polyester film
- Can let light bleed through and distort the stencil
4. Waterproof Inkjet Transparency Film
- Premium option for professional screen printers
- Waterproof coating ensures ink doesn’t smudge
- Provides high opacity and clarity
- Industry standard for most modern shops
5. Photographic Film (Older Methods)
- Before digital printing, designs were created using photographic film and darkroom techniques
- Rarely used today but still relevant in specialized art printing
Which Film Is Most Commonly Used Today?
In modern screen printing, the most widely used film is waterproof inkjet transparency film.
Why? Because it offers:
- High ink density (deep, opaque blacks)
- Waterproof coating (prevents smearing)
- Compatibility with standard inkjet printers
- Ability to handle halftones and fine details
This makes it the go-to choice for both professionals and hobbyists.
How to Print on Screen Printing Film
Simply having the right film isn’t enough—you also need the correct setup to print your designs onto it.
Printer Options
- People often use inkjet printers for this, and Epson pigment-ink machines are the most popular.
- Laser printers work but may lack opacity.
Ink Density (Opacity)
- The black areas must be opaque enough to block UV light.
- RIP (Raster Image Processor) software helps make blacks look deeper and makes sure that halftone dots are placed correctly.
Design Preparation
- Save files in high resolution (300 DPI or more).
- For multi-color prints, print separate films for each color layer.
Film Quality Considerations
When choosing a film, keep these factors in mind:
- Transparency: Clear films ensure sharp edges during exposure.
- Opacity: Dense black areas prevent unwanted light leakage.
- Durability: Thicker films last longer and resist curling.
- Storage: Films should be stored flat and away from dust, heat, or moisture.
Alternatives to Film in Modern Screen Printing
Some advanced shops now use direct-to-screen (DTS) systems, which eliminate the need for physical film altogether. You can also use specific tools to digitally image the design straight onto the emulsion-coated screen.
While efficient, DTS machines are very expensive and usually only found in high-volume production facilities. For most small and medium-sized operations, film positives remain the standard.
Common Problems with Screen Printing Films
- Ink Not Drying: Low-quality film may not absorb ink properly, causing smudges.
- Light Bleeding: Thin or low-opacity films let too much light through, resulting in fuzzy edges.
- Registration Issues: If films warp or curl, aligning multiple colors becomes difficult.
Tips for Choosing the Best Film
- Use film that works with your printer (inkjet or laser) every time.
- Look for films labeled “waterproof inkjet transparency film” for best results.
- Test different brands for opacity and detail sharpness.
- Never skimp on quality; better film lowers the chance of ruining screens.
Frequently Asked Questions (FAQs)
Q1: Is it possible to use regular transparencies for screen printing?
Technically, yes—but they don’t achieve the same ink density as specialized films. Your stencils may come out blurry.
Q2: How long do screen printing films last?
If stored properly, films can last for years. However, repeated use may cause scratches or warping.
Q3: What is the difference between vellum and inkjet film?
Vellum is paper-based and cheaper but less reliable. Inkjet film is polyester-based and produces higher-quality results.
Conclusion
So, which film is used in screen printing?
The answer is clear: while several types exist, the most common and reliable choice today is waterproof inkjet transparency film. Inkjet film is the greatest choice since it is cheap, easy to use, and prints well.
Whether you’re a beginner setting up your first home studio or a professional running a print shop, investing in the right film ensures sharper stencils, cleaner prints, and a smoother workflow. Remember: the better your film, the better your final prints.