Last updated: October 2026
Quick answer: A PS plate is exposed through film on an exposure frame; a CTP plate is imaged directly from digital files by a platesetter, with no film. CTP gives sharper, more repeatable dots and fewer remakes, while PS needs the lowest equipment investment. If your film line still works and volumes are small, PS is reasonable; for growing volume or tighter quality, move to thermal CTP or CTcP.
Key takeaways
- The core difference is the image source: film plus exposure frame (PS) versus a laser or UV platesetter writing the file directly (CTP).
- We manufacture positive PS plates only; we do not supply negative PS plates.
- CTcP plates are imaged by a UV platesetter and are the gentlest step up from PS for shops that want to drop film.
- Compare total cost per usable plate (film, chemistry, remakes, labour), not just the plate price.
- Gauges 0.15, 0.20, 0.25 and 0.30 mm are standard for both families; MOQ and price are confirmed in the quotation.
Many printing houses still run a film line next to, or instead of, a platesetter. The question we hear most often from purchasing managers is simple: “Our film equipment still works, so why change?” Others tell us film costs keep rising and that dust and film defects cause remakes every week. This article compares the two plate families side by side, explains where each one fits and shows how to move from PS to CTP without changing everything at once. For a wider overview of plate families, see our guide to the different types of CTP plates.
CTP plate vs PS plate: decision table
| Criterion | PS plate (presensitized) | CTP plate (thermal or CTcP) |
|---|---|---|
| Image source | Film positive on a vacuum exposure frame | Digital file imaged by a platesetter (830 nm thermal laser or UV) |
| Film and film processing | Required | Not required |
| Dot reproduction | Depends on film quality, vacuum contact and lamp condition | Direct imaging, more repeatable highlight and shadow dots |
| Handling light | Yellow safelight until development | Thermal: normal room light within TDS limits; CTcP: yellow safelight |
| Processing | PS developer, rinse, gum | Plate processor with CTP developer (or none for processless thermal) |
| Equipment investment | Low (exposure frame, simple processor) | Higher (platesetter, RIP, processor) |
| Typical remakes | Dust, scratches, film defects, undercutting | Mostly file or calibration errors |
| Best fit | Small runs, existing film line, low daily plate count | Growing volume, fine screens, colour-critical work |
What is a PS plate?
PS stands for presensitized. The grained, anodised aluminium plate is supplied already coated with a light-sensitive layer. You place a film positive on the plate, pull vacuum in an exposure frame, expose with a UV lamp and develop the plate in PS developer. Exposed areas dissolve, and the unexposed coating stays behind as the ink-receiving image.
Our positive PS plates are made in our own factory in standard gauges and cut to size. We do not supply negative PS plates. If your press room was built around negative film, talk to us before ordering so we can review the alternatives honestly; our article on positive vs negative printing plates explains the difference.
What is a CTP plate?
CTP (computer-to-plate) plates are imaged directly from the digital file. There is no film, no step-and-repeat on a frame and no vacuum contact problem. Two families cover most offset printing today:
- Thermal CTP plates imaged at 830 nm on a thermal platesetter. Our thermal CTP plate range includes single-layer, double-layer and processless grades.
- CTcP plates (computer-to-conventional plate) imaged with UV light on a UV platesetter. The coating chemistry is close to a conventional plate, which is why CTcP is often the first step away from film. We manufacture single-layer CTcP plates; we do not supply a double-layer CTcP plate.
The platesetters themselves are supplied with our partner factories. If you are pricing a complete line, our CTP machine overview lists the thermal, UV and violet options.
When to choose PS plates
PS plates remain a sensible choice in specific situations. They are not “old” plates in a negative sense; they simply belong to a film-based workflow.
- Your exposure frame and film processor are in good order and the operators know them well.
- Daily plate count is low and jobs are simple (one- or two-colour, text, forms, local commercial work).
- You want to keep using your existing exposure frame while budgeting for CTP next year.
- Your customers send film or you buy film output from a local bureau.
The common objection is that “PS plates are cheaper per plate.” That is often true for the plate alone. The real cost per usable plate also includes film, film chemistry, remakes caused by dust or poor contact, and the time an operator spends on each exposure.
When to choose CTP plates
Buyers who move to CTP usually want sharper dots and faster plate making, and they want the same result on Monday and Friday. CTP fits when:
- You print four-colour work with fine screens where dot reproduction must stay consistent.
- Plate volume is growing and film handling is a bottleneck.
- Remakes from film defects, dust or undercutting cost you press time.
- Your clients send PDF files and expect fast proof-to-plate turnaround.
Within CTP, thermal plates suit most commercial and packaging work, and double-layer thermal grades are the choice for UV inks and the longest baked runs. Single-layer thermal and CTcP plates can be baked but are not UV-ink resistant, even after baking. Our plate selection guide walks through those choices by press and ink.
Can you switch or run both?
Yes, and many plants do. A frequent objection is “CTP is too expensive for a small shop” or “my operators only know the film workflow.” Moving to CTP does not have to mean replacing the whole plate room at once. A gradual path looks like this:
- Keep PS running for simple jobs while you qualify CTP plates on colour work.
- Choose the platesetter family first. A UV (CTcP) platesetter keeps your plate chemistry close to what operators already know; a thermal platesetter gives daylight handling and access to processless plates.
- Check your processor. Some processors can be reset for CTP developer; otherwise a dedicated CTP plate processor keeps the two chemistries apart.
- Run trial plates on your press with your ink and paper before switching volume.
- Retire film gradually as CTP volume grows.
Running both is fine as long as each plate type goes through the correct developer. Mixing PS and CTP plates in one developer bath without checking the TDS is a common cause of under- or over-development.
Cost and workflow factors
We do not publish prices on this page, because plate price depends on grade, gauge, size and volume and is confirmed in the quotation. These are the factors to compare when you build your own cost per usable plate:
| Cost factor | PS workflow | CTP workflow |
|---|---|---|
| Plate | Positive PS plate | Thermal, processless or CTcP plate |
| Film and film chemistry | Yes, per job | None |
| Equipment | Exposure frame, processor | Platesetter, RIP, processor (or none for processless) |
| Labour per plate | Manual film mounting and exposure | Mostly automatic imaging |
| Remakes | Dust, contact, film damage | File and calibration errors |
| Developer | PS developer | CTP developer or none |
For a structured comparison, our plate cost calculator helps you add film, chemistry and remakes to the plate price. If you are also budgeting equipment, read our notes on CTP machine price factors.
FAQ
What is the difference between a CTP plate and a PS plate?
A PS plate is exposed through film on an exposure frame, while a CTP plate is imaged directly from a digital file by a platesetter, with no film. CTP removes film costs and film defects and gives more repeatable dots.
Is a CTP plate better than a PS plate?
For fine screens, growing volume and colour-critical work, CTP is usually the better choice. For small shops with a working film line and simple jobs, PS plates are still economical. Compare total cost per usable plate, not plate price alone.
Can PS plates be used on a CTP machine?
Standard PS plates are made for film exposure on an exposure frame, not for a thermal platesetter. A UV (CTcP) platesetter images CTcP plates, which have a coating designed for UV direct imaging. Ask for trial plates matched to your platesetter type.
Is CTcP the same as a PS plate?
No. CTcP plates use a conventional-type coating like PS, but they are designed to be imaged directly by a UV platesetter without film. We manufacture single-layer CTcP plates and do not supply a double-layer CTcP plate.
Are PS plates still used in printing?
Yes. PS plates are still used where film equipment is in good order, plate counts are low and jobs are simple. We manufacture positive PS plates only and do not supply negative PS plates.
How much does it cost to switch from PS plates to CTP?
The cost depends on the platesetter type, format, automation level and whether your processor can be reused. We quote the platesetter supplied with our partner factories, plates and processing equipment together, and prices are confirmed in the quotation.
Planning a move from film to CTP, or simply need a reliable PS plate supply? Request a quote — send your plate size, gauge, monthly volume, platesetter or exposure frame and the inks you run. Or request trial plates / contact us.
Disclaimer: values on this page are typical and for reference only; final specifications, MOQ, price and lead time are subject to the grade TDS and the quotation.
