Paper and Film Coating Services – From Brief to Quality Control
Contract (toll) coating of paper and film is a service in which the manufacturer applies a silicone or adhesive layer to an agreed substrate according to parameters defined by the customer, then slits, prints and converts the material into a form ready to run on the production line. At DOLPAP we apply silicone coatings up to 1600 mm wide and water-based adhesive coatings up to 1000 mm wide, we slit rolls from 15 mm (papers) and 30 mm (films) up to 1600 mm, and we confirm every coating parameter in our own laboratory. Below we walk through the entire process step by step: from the technical brief, through substrate and coating selection, to the trial lot, series production and quality control.
What is toll coating and when does it pay off?
Toll coating – also described as contract coating or converting – means the customer supplies the specification, and sometimes the raw material, while the supplier provides the production line, the process know-how and the quality control. The result is not a catalogue product but a material engineered for one specific process: with a defined release force, grammage, width and winding.
This model makes sense in three typical situations. The first is the absence of a standard equivalent on the market – when the process calls for an unusual combination of substrate and coating, or a very narrow release window. The second is the CapEx versus OpEx calculation: an in-house coater means investment, floor space, staffing and maintenance, whereas contract coating converts a capital cost into a unit material cost. The third is supply chain length – coating, slitting, printing and testing carried out in a single plant remove inter-process transport, multiple suppliers and blurred responsibility for quality.
Step 1. The technical brief – what data to prepare
The quality of the quotation and the speed of implementation depend above all on how complete the brief is. The more process data we receive at the start, the fewer iterations before the trial lot. It is worth preparing:
- Base substrate – material type (glassine, kraft, CCK, PCK, offset paper, PE-coated paper, PET, PP, PE or creped PP film) together with its grammage or thickness.
- Coating type – silicone (one- or two-sided, solventless or UV technology) or water-based adhesive; for silicone, also the expected release level: easy release or controlled release.
- Target adhesive or compound – acrylic, rubber, hot-melt, butyl or silicone adhesives. This is one of the most important parameters: the release coating is always matched to the adhesive system it will work with.
- Process conditions – line temperature and speed, unwinding method, web tension, the presence of die-cutting or matrix stripping, and any food-contact requirements.
- Target dimensions – working roll width, roll diameter, core diameter, winding direction, and where relevant the sheet format or die-cut shape.
- Volume and schedule – annual demand, single lot size, expected delivery frequency, plus pallet packing and labelling requirements.
If some of this data is not yet available, it is not an obstacle – parameter selection is the job of our process engineering team and our R&D centre. The brief is a starting point for the conversation, not a knowledge test.
Step 2. Selecting the substrate and the coating
This is where most of the cost is decided. A paper substrate is the choice where price, recyclability and smooth machine running matter: glassine offers a smooth, semi-transparent surface at low grammage, kraft provides natural strength, CCK (Clay Coated Kraft) gives a stable, closed surface for an even coating, and PCK (Poly Coated Kraft) adds a polyethylene barrier. Grammages span 35 to 160 gsm (glassine 35–160, kraft 35–50, CCK 40–135, PCK 60–150 gsm) and colours include white, brown, yellow and topaz, with availability depending on the substrate type.
A film substrate is chosen where dimensional stability, transparency or thermal resistance are required: PET holds its geometry under high temperature and tension, PP is lighter and more economical, PE is soft and resistant to mechanical damage, and creped PP adapts flexibly to uneven surfaces. Typical thicknesses run from 8 to 100 µm, most often 12, 23, 36, 50, 60, 75 and 80 µm.
On the coating side, the decision concerns technology and configuration. Solventless and UV siliconising produce a repeatable layer with a controlled release force, applied on one or both sides, including versions with differential release on each face of the material. Water-based adhesive coating is used for gummed papers and water-activated tapes, where the plant-based adhesive layer stays inactive until it is moistened.
DOLPAP coating, slitting and converting parameters
| Service / parameter | Range |
| Silicone coating | up to 1600 mm wide, one- and two-sided, solventless and UV technology |
| Water-based adhesive coating | up to 1000 mm wide, water-based adhesives (gummed papers, water-activated tapes) |
| Release level | easy release, controlled release, differential release |
| Paper substrates | glassine 35–160 gsm, kraft 35–50 gsm, CCK 40–135 gsm, PCK 60–150 gsm, PE-coated paper |
| Film substrates | PET, PP, PE and creped PP films – 8–100 µm (most often 12–80 µm) |
| Slitting | rolls from 15 mm (papers) and 30 mm (films) up to 1600 mm, sheets cut to size, die-cuts in irregular shapes |
| Converting | rolls, spools, sheets, die-cuts; winding and cores matched to the customer’s machine |
| Printing | single- and multi-colour: production codes, batch numbers, tear-direction markings, logos |
| Laboratory testing | release force and coating adhesion, coating thickness and uniformity, smoothness, weather resistance |
Step 3. Coating – what happens on the line
The plant operates three coating machines and four rewinders; the newest coater – a UV silicone coating line commissioned in 2024 – has a working width of 1620 mm. This machine park lets us run series production and process trials in parallel, without stopping current orders for the duration of a test.
The process itself is precise application and curing: the silicone or adhesive mix is fed onto the web, metered to the required coat weight and cured – thermally or by UV radiation. Two factors are critical: evenness of application and complete curing. An under-cured coating migrates into the adhesive layer and reduces its adhesion over time, while an uneven coating produces release force differences across the web. That is exactly why control does not end with visual inspection, but continues in the laboratory.
Step 4. Slitting paper and film – from jumbo roll to working format
Slitting is the stage at which the material is adapted to the customer’s machine. We slit jumbo rolls into narrower rolls – from 15 mm for papers and 30 mm for films, up to 1600 mm; we cut sheets to formats matched to printing, packing and labelling machines; and we produce die-cuts in irregular shapes. We handle materials across a wide range of grammages and thicknesses: silicone release papers, gummed papers, PE-coated papers and films.
From a cost perspective, two points deserve attention. First, precisely matching the width to the die-cut layout reduces edge waste – instead of adapting the process to an available format, the format is adapted to the process. Second, the right roll diameter and core shorten changeovers: fewer roll changes per shift mean real minutes recovered on every machine. We agree these parameters with the customer before the first production lot.
Step 5. Technical printing and batch identification
Printing on coated material is usually functional rather than decorative. We apply production codes and batch numbers, tear-direction and coated-side markings, product information, warnings and logos, in single- or multi-colour versions. The print has to survive contact with adhesive and mechanical stress in the process, so inks are selected for abrasion resistance and resistance to adhesive compounds.
For many customers, however, traceability matters most. Batch marking on the material links every roll to a specific production run and its test results, which can shorten root-cause analysis in a complaint from weeks to hours.
Step 6. Laboratory testing and quality control
Our in-house laboratory and R&D centre allow us to confirm material parameters rather than simply declare them. The scope of testing covers above all:
- Coating parameters – release force and coating adhesion, coat thickness and uniformity, surface smoothness, resistance to weather conditions.
- Analysis before and after coating – comparison of the base substrate and the finished product, including the effect of the process on mechanical strength.
- Testing of new raw materials and solutions – evaluation of alternative substrates or coating systems before they enter series production.
- Production quality monitoring – regular measurements during order fulfilment, within a system compliant with PN-EN ISO 9001:2015.
Test results within the agreed scope are supplied as part of the technical documentation for the lot. For the customer this means the material can be verified independently of commercial claims and, during implementation, provides an unambiguous criterion for moving from trial to series production.
From sample to series production – how implementation works
The standard implementation path has four stages. First, the brief and a preliminary quotation based on process parameters. Second, a sample or trial lot that the customer tests on their own line – under target conditions, with the target adhesive and at production speed. Third, validation of the results and any correction of parameters, most often release force, coat weight or winding. Fourth, approval of the specification and the start of series production with an agreed delivery schedule.
In practice, the biggest time saving comes from testing the target material rather than the closest available substitute. A release force difference of ten to twenty per cent may be invisible in the laboratory yet stop the line at production speed – and the reverse is equally true: a material that performs on a slow test run may need a different coating at full speed.
The most common mistakes in coating enquiries
Four mistakes keep recurring. The first is omitting the target adhesive – without it, selecting the release level is guesswork. The second is quoting only the trade name of the current material without its parameters; names change, parameters remain. The third is leaving out storage and transport conditions, which genuinely affect how silicone and gummed coatings behave. The fourth is testing too late – ordering a production lot without a prior process trial moves the risk to the point where correction is most expensive.
Why DOLPAP?
We have been coating since 1977, when a department for coated papers and self-adhesive materials was set up at our plant in Chojnów, Poland. Today we run three coating machines – including a UV line commissioned in 2024 with a working width of 1620 mm – together with four rewinders and dedicated slitting and converting equipment. Every order is checked in our in-house laboratory, and new process solutions are developed in our R&D centre, in cooperation with the Wrocław University of Science and Technology since 2010. We work to a system compliant with PN-EN ISO 9001:2015 and PN-ISO 45001:2018. Coating, slitting, printing and laboratory testing all take place under one roof – so a single supplier answers for the material parameters, rather than a chain of subcontractors.
FAQ – paper and film coating services
What is the maximum coating width?
We apply silicone coatings to materials up to 1600 mm wide; the UV line commissioned in 2024 has a working width of 1620 mm. Water-based adhesive coatings are applied up to 1000 mm wide.
Can I have my own substrate coated?
Yes, we take orders both on customer-supplied material and on substrates sourced by us. In both cases we run a process trial and laboratory testing before series production.
Which substrates can be coated?
Glassine, kraft, CCK and PCK papers and PE-coated papers from 35 to 160 gsm depending on the substrate type, as well as PET, PP, PE and creped PP films in thicknesses from 8 to 100 µm.
What release levels are available?
We offer easy release and controlled release, including materials with differential release on each side. The exact value is matched to your adhesive system and line speed.
Do you slit and convert after coating?
Yes. We slit rolls from 15 mm (papers) and 30 mm (films) up to 1600 mm, cut sheets to size and produce die-cuts, and we convert the material into rolls, spools, sheets and die-cuts, with winding and cores matched to the receiving machine.
What tests are performed before dispatch?
As standard we check release force and coating adhesion, coating thickness and uniformity, smoothness and weather resistance. The scope can be extended with tests agreed individually at the brief stage.
Can printing be ordered on coated material?
Yes – we offer single- and multi-colour printing: production codes, batch numbers, tear-direction markings and logos, using inks resistant to abrasion and to adhesive compounds.
How long does implementing a new material take?
It depends on the complexity of the specification and the number of test iterations. Completeness of the brief and availability of the base substrate have the greatest influence on the timeline, so we agree the schedule individually after the first technical review.
Planning to outsource coating, slitting or printing? Contact us – we will review your process parameters, propose a substrate and coating, and prepare a sample for testing on your own line.
