5Mil Waterproof Clear Positive Film for Screen Printing: 13"x19" Sheets vs 24"x100ft Roll — Which Should You Choose?

5mil waterproof clear positive film for screen printing is a 4-mil PET film with a 1-mil microporous ink-receptive coating that lets any pigment or dye inkjet printer produce dense, waterproof black positives for screen exposure. It comes in two formats: 13"x19" cut sheets, best for small shops printing positives on demand in mixed sizes, and 24"x100ft continuous rolls, built for high-volume shops running large-format printers daily. Both use the same waterproof, anti-curl coating for sharp, UV-blocking blacks. Below, we break down what the film is, how it performs, common mistakes to avoid, and which size actually fits your shop and production volume.

What Is 5Mil Waterproof Clear Positive Film for Screen Printing?

5mil waterproof clear positive film is a transparent inkjet media purpose-built for screen printing prepress. The "5 mil" refers to total thickness — a 4 mil PET (polyester) base laminated with a 1 mil microporous coating that absorbs ink fast while staying water-resistant. When you print black artwork or a halftone separation onto the film, the coating holds enough ink density to fully block UV light, which is what lets you burn a clean, accurate stencil onto photo emulsion.

Unlike plain transparency sheets, this waterproof inkjet film is engineered specifically for screen printing positives — not general office printing — so it holds up under studio humidity, resists smudging before exposure, and produces the sharp edges and solid blacks that a stencil needs.

Benefits of 5Mil Waterproof Clear Positive Film

A few properties make this film worth using over generic printable transparency stock:

High Ink Density for Clean Stencil Exposure

With a max ink density around 3.8 and a transmission density of roughly 0.07, the film produces near-opaque blacks. That density is what actually determines whether your exposure unit burns a crisp stencil or a soft, underexposed one — thin, gray positives are one of the most common causes of screen printing rework.

Waterproof, Anti-Curl Construction

The microporous coating resists moisture, and built-in anti-curl technology keeps sheets and roll-fed sections lying flat during and after printing — important if your shop prints positives ahead of time and stores them before exposure.

Fast Drying, Faster Turnaround

The coating is formulated to dry quickly after printing, so you're not waiting around before you can handle the film or move to exposure. For shops turning multiple jobs a day, that adds up.

Works With Dye and Pigment Inks

The film is compatible with both pigment and dye inkjet printers across most major brands, so you don't need a dedicated printer just for positives.

Common Applications

While screen printing positives are the primary use case, this film shows up across several related workflows:

Silk screen stencil creation with photo emulsion, halftone film and color separations for multi-color garment printing, pad printing and offset prepress work, PCB photo-resist imaging, and even overhead projector transparencies or cyanotype and alternative photographic processes. Any process that needs a UV-blocking, waterproof clear positive can typically use this film.

How to Choose: 13"x19" Sheets vs 24"x100ft Roll

This is the question we get most often, and the honest answer depends on your print volume, printer setup, and how many different job sizes you run in a week.

13"x19" Sheets — Best For Low-to-Medium Volume Shops

The 13"x19" 5mil clear positive film ships as a 100-sheet pack and loads into standard desktop and wide-format inkjet printers without any cutting. It's the better choice if you print positives in small batches, run mixed job sizes, want zero waste from trimming a roll, or are just getting your screen printing setup off the ground. It's also easier to store flat in a drawer or portfolio case next to your aluminum screen printing frames and other prepress supplies.

24"x100ft Roll — Best For High-Volume Production

The 24"x100ft clear positive film roll is built for shops running large-format printers and printing positives daily. Buying by the roll lowers your per-square-foot cost, cuts down on how often you're reordering, and lets you print oversized or multi-image layouts in a single pass instead of tiling sheets together. It's also available in other widths (13", 14", 17", 36", 44", 60", 63"), all at 100 feet, so you can match roll width to your specific printer.

Quick Comparison

If you're not sure which to start with, most new shops start with sheets and move to a roll once they're consistently printing positives multiple times a week. You can browse the full 5mil waterproof inkjet film collection to compare every size side by side.

Common Mistakes to Avoid When Using Clear Positive Film

Even with the right film, a few setup mistakes can ruin an otherwise good stencil:

Printing at Low Quality/Draft Settings

Draft mode saves ink but reduces density, which weakens UV-blocking and leads to underexposed, pinholed stencils. Always print positives at your printer's highest quality black setting, and consider double-printing the same image for extra density on detailed halftones.

Handling the Film Before It's Fully Dry

Even though this film dries fast, touching or stacking sheets too soon can smudge fine detail or transfer ink between layers. Give it a few minutes flat before handling.

Storing Film Improperly

Heat, humidity swings, and direct sunlight degrade the coating over time and can cause curling or fogging. Keep unused film in its original packaging, in a cool, dry space, ideally at 60–80°F and 40–60% relative humidity.

Mismatching Frame and Mesh to the Film's Detail Level

A high-density positive is wasted if your screen setup can't hold that detail. Pair your film with a properly tensioned pre-stretched aluminum frame and the right screen printing mesh count for your design — fine halftones need a higher mesh count than bold single-color art.

Using the Wrong Ink Type for Your Printer

While the film supports both pigment and dye inks, pigment ink generally produces denser, more UV-opaque blacks. If your stencils are consistently coming out underexposed, check your printer's ink type and driver settings before blaming the film.

FAQs

What does "5 mil" mean for positive film thickness?

Mil is a unit equal to one-thousandth of an inch. This film measures 5 mil total: a 4 mil PET base plus a 1 mil ink-receptive coating. That thickness gives it enough rigidity to feed smoothly through printers while staying flexible enough to lie flat against a screen during exposure.

Is 5mil clear positive film really waterproof?

Yes. The microporous coating is formulated to resist moisture and humidity once the ink is dry, which prevents smudging or ink bleed in typical shop conditions. It's water-resistant rather than fully submersible, so it should still be stored away from direct water contact.

Can I use this film with a regular desktop inkjet printer?

Yes. The film is compatible with most dye and pigment inkjet printers, from desktop models up to large-format roll-fed machines. The 13"x19" sheets are sized to fit standard desktop and wide-format printer trays without trimming.

Should I choose pigment or dye ink for the best black density?

Both work, but pigment ink typically produces denser, more UV-opaque blacks, which generally means cleaner stencil exposure. If your stencils are coming out soft or underexposed, switching to pigment ink is one of the first things to try.

What's the actual difference between the 13"x19" sheets and the 24"x100ft roll?

Both are the same 5mil waterproof film — the difference is format. Sheets are pre-cut and ready to load with zero trim waste, ideal for lower volume or mixed-size jobs. The roll is more economical per square foot and suited to shops printing large or high-volume runs on a large-format printer.

How long does a printed film positive last before I need to expose the screen?

Once fully dry, a positive can be stored flat for weeks without meaningful density loss if kept away from heat, humidity, and direct sunlight. For best results, expose within a few days and store in the original packaging or a dark folder in between.

Can this film work with a laser printer instead of inkjet?

No — this is an inkjet-specific coating designed to absorb liquid ink. Running it through a laser printer's heat and toner process can damage the coating or the printer itself. For laser printing, you'll want a laser-compatible transparency film instead.

Do you offer custom sizes or bulk rolls for high-volume shops?

The roll is available in multiple widths (13", 14", 17", 24", 36", 44", 60", and 63"), all at 100 feet long, so most high-volume shops can match a width to their printer without a custom order. Reach out to our team if you need a size outside that range.

How should I store unused film to prevent curling or fogging?

Keep it in its original packaging, away from direct sunlight, at roughly 60–80°F and 40–60% relative humidity. Avoid stacking heavy items on top of sheets or rolls, and reseal packaging after each use.

Buying Guide: Getting the Right Film for Your Shop

If you're outfitting a new press or restocking prepress supplies, it's worth ordering your film alongside the rest of your screen setup. SHL Supply ships both the 13"x19" sheet pack and the 24"x100ft roll from a US-based warehouse, so domestic orders don't wait on overseas freight. Custom roll widths and OEM/private-label packaging are available for shops and resellers with recurring volume — contact our team to discuss specs and lead times.

Ready to order? Browse the full 5mil waterproof clear positive film collection, or pair your film with aluminum screen printing frames and screen printing mesh to complete your setup. Have a question about which size fits your printer or production volume? Send us your specs and we'll help you choose.