Key flexing
Repeated key movement and embossing influence film and coating selection.
Select film from real use conditions
Polyester vs Polycarbonate Graphic Overlays
Polyester is often considered where repeated flexing and chemical durability are important; polycarbonate offers different forming, printing and appearance options. The correct choice depends on the specific grade, hard coat, thickness, forming, cleaning and environmental conditions—not the polymer name alone.
Engineering variables
Material questions
Appearance
Gloss, matte, texture, transparency and print effects vary by grade.
Chemical exposure
Name the cleaner, concentration, contact time and frequency.
Supply evidence
Any compliance or performance claim must match the actual supplier grade.
Decision matrix
Choose the film from the finished overlay—not the polymer name.
Use this matrix to expose the trade-offs that must be confirmed for the selected supplier grade, coating, print stack and mounted sample. Neither polymer is a universal winner.
| Decision factor | Polyester (PET) | Polycarbonate (PC) |
|---|---|---|
| Best starting fit | Interfaces with repeated key flexing and defined cleaning exposure, subject to the selected grade and coating. | Overlays needing forming, embossing, appearance or process flexibility, subject to the selected grade and coating. |
| Key movement | Prioritise repeated flexing with approved key geometry, coating and support conditions. | Forming and embossing may suit the process, but the actuating construction still requires mounted-sample approval. |
| Surface and cleaning | Specify the hard coat and texture, then test the actual cleaner, contact time and cleaning frequency. | Specify the hard coat and texture, then test the actual cleaner, contact time and cleaning frequency. |
| Printing and forming | Confirm ink adhesion, dimensional behaviour, die cutting and embossing for the actual film grade. | Confirm ink and coating compatibility plus the forming, die-cutting and embossing route for the actual film grade. |
| Approval evidence | Record the supplier grade and review the printed, coated sample in the real mounted and exposure conditions. | Record the supplier grade and review the printed, coated sample in the real mounted and exposure conditions. |
Hard coat, texture, print system, adhesive, thickness and supplier grade can change the result. Record the exact construction on the approved drawing.
Before the RFQ
Questions that keep the first review useful.
Start with the evidence you have now. Open items stay visible for engineering follow-up instead of becoming silent quotation assumptions.
Is polyester or polycarbonate always better for a graphic overlay?
No. Polyester is a useful starting point when repeated key flexing or a defined chemical exposure drives the risk; polycarbonate can be useful when forming, rigidity or a particular optical construction matters more. The exact grade, coating, print stack and mounted use condition decide the project choice.
Does a hard coat make polyester and polycarbonate interchangeable?
No. A hard coat changes the exposed surface, but the base film, coating chemistry, finish, thickness, forming and printing process still affect the result. Compare named supplier constructions under the same cleaner, abrasion, flexing and optical acceptance methods.
What should the drawing record before an overlay film is approved?
Record the supplier grade, thickness, hard coat and finish, print and window construction, embossing or forming, adhesive interface, named exposures and acceptance evidence. Approve the printed and mounted sample rather than a generic PET or PC description.
A useful fit when
Start here if the project has these conditions.
- Graphic overlay material selection
- Cleaning-resistance reviews
- Artwork and embossing development
Limits to resolve
Do not treat a product page as a final specification.
- Generic polymer comparisons are not material certificates
- Hard coats and printing change surface behaviour
- Customer testing may be required for the final exposure
Prepare the RFQ
What to send for a useful review
You can submit what is available now. Unknown items remain visible for human follow-up rather than being guessed.
- 01
Current film grade if specified
- 02
Cleaning and environmental exposure
- 03
Embossing and key-use requirements
- 04
Appearance and compliance evidence needed
Evidence boundary
Claims follow the approved drawing and the actual evidence holder.
Material statements are confirmed from the selected supplier grade and project evidence before they appear in a quotation or specification.
Technical reference basis
Sources inform the questions. The project drawing controls the answer.
These publisher resources support the decision framework. They do not prove that HYR uses a named grade, holds a listed certification or has approved a project construction.
- MacDermid AlphaAutoflex EB Gloss & Antiglare — hardcoated polyester ↗Publication date not stated
Primary supplier context for one named hardcoated polyester family; it is not evidence that HYR uses this grade or that every polyester construction has the same properties.
- MacDermid AlphaAutoflex PC Gloss & Antiglare — hardcoated polycarbonate ↗Publication date not stated
Primary supplier context for one named hardcoated polycarbonate family; it is not evidence that HYR uses this grade or that every polycarbonate construction has the same properties.