Kapton® Film Guide: Thickness, Width and Applications
Kapton® film is a non-adhesive polyimide film used where thin electrical insulation, a flexible substrate, or a heat-resistant film is required. It is different from Kapton® tape: tape adds an adhesive layer, changing total thickness and the temperature limit of the finished construction.
Shop the material: Kapton® film rolls in 1, 2 or 5 mil thickness, 12, 24 or 36 inch width, and 25, 50 or 100 foot lengths. Select the roll length on the product page; the quantity is the number of rolls.
Choose film thickness
One mil is one thousandth of an inch, or about 25 micrometres. Our available film thicknesses are 1 mil (about 25 µm), 2 mil (about 51 µm), and 5 mil (about 127 µm). Choose according to your design's electrical, mechanical, flexibility and dimensional requirements; a larger thickness number is not a substitute for testing the finished assembly.
| Film thickness | Approximate metric thickness | Available widths |
|---|---|---|
| 1 mil | 25 µm | 12, 24, 36 in |
| 2 mil | 51 µm | 12, 24, 36 in |
| 5 mil | 127 µm | 12, 24, 36 in |
Film versus tape
Use film when you need a non-adhesive sheet to cut, form, laminate or incorporate into another assembly. Use Kapton® tape when a pressure-sensitive silicone adhesive is needed for immediate attachment. For example, our 1 mil tape has 1 mil film backing but is 2.5 mil total thickness. The distinction also matters for heat exposure: a film-only application figure is not the finished tape's operating rating. Read our film versus tape guide and Kapton® tape selection guide.
Where film is used
DuPont's Kapton® summary of properties lists electrical insulation applications such as formed coil insulation, motor slot liners, transformer and capacitor insulation, and flexible printed circuit substrates. For a finished part, check the exact film type, testing method and any additional coatings, adhesives or laminates. Our film roll product page lists the thicknesses, widths and roll lengths currently offered; request the relevant technical documentation before specifying a grade or performance limit.
Ordering film rolls
- Choose 1, 2 or 5 mil film thickness.
- Choose 12, 24 or 36 inch width.
- Choose a 25, 50 or 100 foot roll length.
- Enter the number of rolls as quantity. For example, quantity 2 with 25 ft selected orders two 25-foot rolls.
- Check the selected roll price before checkout.
Need a different cut size, documentation, or a converted shape? Contact us with your width, thickness, length and application or explore Kapton® die cuts. Kapton® is a registered trademark of DuPont or its affiliates.
How to specify film for a project
- Identify the construction. Determine whether you need bare film, an adhesive-backed tape, a coated film or a laminated assembly. These are not equivalent even when they contain polyimide.
- Set the width and thickness. Select from our listed 12, 24 and 36 inch widths and 1, 2 and 5 mil film thicknesses. If the shape must fit a tight clearance, include tolerances in the request.
- Describe the environment. Provide operating temperature, exposure duration, mechanical loading, electrical test requirements and any downstream processing.
- Plan cutting and conversion. A roll can be useful for your own cutting. For repeatable shaped parts, ask about converting or use our standard die cuts.
- Validate the finished assembly. An adhesive, coating, metal layer or substrate may determine the final assembly's operating limits.
Width and length: what does the quantity mean?
The price on the film product is per roll for the selected width, thickness and length. A 24-inch wide, 25-foot roll covers 50 square feet in area; a 12-inch wide, 25-foot roll covers 25 square feet. Cart quantity counts rolls, so quantity 2 means two rolls of the selected length. Confirm all three options before comparing prices or checking out.
What does the manufacturer data apply to?
The Kapton® properties bulletin presents several film types, including HN, HPP-ST and FN. Their constructions and tables differ. Do not assign a property value from one type to another, or assume the film roll listing is a particular grade without matching technical documentation. DuPont's high-temperature examples describe film use under specified conditions; they do not certify a customer's final laminate or adhesive system.
Frequently asked questions
Does this film have adhesive?
No. The current film roll product is non-adhesive film. For a ready-to-apply adhesive product, see Kapton® tape.
Is 1 mil equal to 1 millimetre?
No. A mil is 0.001 inch, approximately 25.4 micrometres. One millimetre is about 39.4 mils.
Can I order a different width or a die-cut part?
The online options are 12, 24 and 36 inches wide. Ask for a custom quote if your project needs a different dimension, converting operation or documentation.