Last updated: October 2026
Quick answer: A processless plate develops on press: fountain solution softens the unexposed coating and ink tack lifts it away during the first sheets. A clean start-up depends on the sequence: dampening first, then ink, then paper, as set in the grade TDS. Most start-up faults come from fountain solution condition, roller settings or a dirty blanket, not from the plate.
Key takeaways
- Processless plates image at 830 nm on a standard thermal platesetter and go straight to press with no processor.
- Write one start-up routine every press operator follows, based on the grade TDS and your own trial.
- The image on the plate has low contrast; check it with angled light and register marks, not by eye alone.
- Our processless plates can run UV inks after a trial; for the longest baked UV runs, use a double-layer thermal plate.
- Processless plates are not baked.
Many printers move to processless plates because developer chemistry and waste disposal cost too much and processor upkeep takes operator time. The first week on press decides whether the change sticks. If the plate keeps toning on the first sheets, operators lose confidence and say processless plates cannot handle real production. More often than not, the cause is the start-up routine rather than the plate. This guide gives a start-up sequence, a troubleshooting table and the mistakes to avoid. For background on the plate itself, see our processless CTP plates page.
How on-press development works
A processless plate carries a heat-sensitive coating on grained, anodised aluminium. The thermal platesetter’s 830 nm laser anchors the exposed coating as the image. The unexposed coating stays soluble in the dampening and ink system, so it is removed on press instead of in a developer bath:
- Fountain solution wets the plate and softens the non-image coating.
- Ink rollers come on, and ink tack lifts the softened coating.
- The removed coating travels to the blanket and leaves on the first waste sheets.
- After clean-up, the plate prints like a developed plate.
Because development happens on press, the order and timing of dampening and inking matter more than with processed plates.
Before the first plate: press and plate room checklist
| Area | Check | Why it matters |
|---|---|---|
| Platesetter | Exposure energy and focus set to the grade TDS; calibration curve made for this plate | Under-exposure leaves a weak image that can wear on start-up |
| Plate room | Handling light and storage within TDS limits; plates kept in their boxes | Unprocessed coating stays sensitive until press |
| Fountain solution | Fresh, correctly mixed, within the press and fount supplier’s conductivity and pH range | Exhausted or contaminated fount slows clean-up and causes toning |
| Rollers | Dampening and form roller settings checked; rollers clean | Uneven contact gives uneven development |
| Blanket | Clean, correct packing, no glazing | Coating debris collects on the blanket |
| Ink | Ink type confirmed (conventional or UV) against the trial plan | UV inks need a trial first |
Step-by-step processless plate start-up
- Image the plate on the thermal platesetter at the TDS exposure settings. Punch and bend it on your plate punch and plate bender as for any thermal plate.
- Check the image. The latent image is faint. Hold the plate under angled light, check register marks and a control strip, and confirm it is the right plate for the unit.
- Mount the plate with clean, dry gloves. Do not wipe, gum or wet the plate before mounting.
- Dampening first. Engage the dampening rollers for the number of revolutions given in the grade TDS, so fountain solution softens the non-image coating.
- Ink second. Engage the ink form rollers for the recommended revolutions. Ink tack starts to lift the softened coating.
- Paper third. Start feeding sheets. The first waste sheets carry the removed coating away.
- Watch the clean-up. Check that background areas clear evenly across the sheet. Adjust ink and water balance only after clean-up is complete.
- Record your routine. Note revolutions, waste sheets and fount settings for each press, and make it the standard routine.
Your goal is clean sheets quickly after start-up and the same result for every operator. A short written routine at each press does more than any adjustment to the plate.
Processless start-up troubleshooting table
| Symptom | Likely cause | What to do |
|---|---|---|
| Toning on the first sheets that does not clear | Ink engaged before dampening; exhausted fountain solution | Follow dampening-ink-paper order; change and remix fount |
| Slow clean-up across the whole plate | Too little dampening at start; low dampening roller pressure | Check roller settings; follow TDS revolutions |
| Local patches stay toned | Uneven roller contact; fingerprints or moisture on the plate | Check roller stripes; handle plates by the edges with gloves |
| Weak or missing fine dots | Under-exposure or wrong calibration | Check platesetter energy and curve against the TDS |
| Coating debris builds up on the blanket | Normal removed coating not cleared; dirty blanket | Wash the blanket on schedule; check fount filtration |
| Operators cannot see the image on the plate | Low-contrast latent image is normal | Use angled light, register marks and job labels on the plate edge |
For faults that also occur on processed plates, our CTP plate troubleshooting guide covers the general causes.
What not to do with processless plates
- Do not run processless plates through a plate processor or apply developer; it damages the coating.
- Do not gum the plate before mounting unless the TDS says so; gum can slow on-press development.
- Do not start ink before dampening, and do not start paper before the rollers have run their revolutions.
- Do not bake processless plates; there is no baking step.
- Do not leave imaged plates in strong light or heat for long periods before press; follow the TDS handling limits.
- Do not change several press settings at once during a trial; change one at a time and record it.
A common objection is that start-up waste will eat the chemistry savings. Measure it: record waste sheets per plate during the trial and compare that cost with developer, processor upkeep and waste disposal. Our plate cost calculator helps you put both sides together.
Running UV inks on processless plates
Our processless plates can run UV inks, but run a trial first on your press with your UV ink, fountain solution and paper. Start-up with UV ink follows the same dampening-ink-paper order. For the longest baked UV runs, a baked double-layer thermal plate remains the safer choice, because processless plates are not baked. Single-layer thermal and CTcP plates are not UV-ink resistant, even after baking. For the full UV picture, see our UV offset printing solutions.
When your press crew will not change their routine, start the trial on one press with one experienced operator, write the routine down, and then roll it out. A structured trial using our plate test protocol gives you numbers from your own press.
FAQ
How do you start up a processless plate on press?
Mount the imaged plate dry, engage dampening first for the revolutions in the grade TDS, then the ink form rollers, then start paper. The first waste sheets carry away the removed coating.
Why is my processless plate toning at start-up?
The usual causes are ink engaged before dampening, exhausted or wrongly mixed fountain solution, or low dampening roller pressure. Fix the start-up sequence and fount condition before suspecting the plate.
Can processless plates run UV inks?
Yes, our processless plates can run UV inks after a trial on your press. For the longest baked UV runs, use a double-layer thermal plate, because processless plates are not baked.
How do you check a processless plate before press?
The latent image has low contrast, so check it under angled light, confirm register marks and a control strip, and label the plate edge with the job and colour.
Do processless plates need a special fountain solution?
Most standard fountain solutions work when fresh and mixed within the press and fount supplier’s conductivity and pH range. Confirm your fount during the trial; exhausted fount slows clean-up.
How many waste sheets does a processless plate need?
It depends on the press, ink, fountain solution and start-up routine. The grade TDS gives the recommended sequence; record your own waste sheets per plate during the trial and use that as your standard.
Planning a processless trial? Request a quote — send your platesetter type, plate size, gauge, press, ink type (conventional or UV) and monthly volume. 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.
