Snel antwoord: in UV varnishes and overprint systems, the right surface-control additive depends on which failure actually matters most. If the film reaches the substrate but still looks rough or patchy, start with a leveling route. If the varnish does not spread cleanly, move toward wetting. If craters, orange peel, or difficult surface-tension behavior remain after ordinary adjustments, fluorine surfactants belong earlier. If the finished layer also needs easier cleaning, marker wipe resistance, or stronger blocking resistance, an anti-graffiti route can be the better fit.
This is not the same decision as the broader CHLUMICRYL® coating- en inktadditieven overview or the narrower Fluor oppervlakte-actieve stof page. This page is for buyers working specifically on UV varnishes, clear topcoats, and overprint systems where gloss, leveling, slip, recoat behavior, and print-surface durability all have to stay inside a tight window.
Why UV varnish and overprint systems need a different additive screen
In the wider market, buyers commonly use additives in overprint varnishes and inks to tune gloss, slip, scratch or rub behavior, and anti-blocking performance. That general framing matches the practical reality of UV varnish work: one additive decision can influence appearance, process stability, and how the final printed surface handles downstream converting or end use.
For Longchang’s current CHLUMICRYL® branch, the supported product pages already show a useful split between:
- leveling and gloss improvement for UV-cure systems,
- wetting and spreading correction for difficult coverage cases,
- fluorine-surfactant routes for varnish compatibility, anti-cratering, slip, and long-wave leveling, and
- easy-clean / anti-graffiti routes when the final varnish layer is also judged by cleanability or blocking resistance.
That makes UV varnish surface control a strong B2B supporting topic instead of a generic additive article.
What buyers are usually trying to fix in UV varnishes and overprint systems
- Orange peel or weak flow-out: the clear layer cures, but the appearance still looks uneven.
- Craters or shrinkage: the surface defects remain visible after basic formulation adjustment.
- Poor wetting or spread: the varnish does not cover or settle consistently over the printed layer.
- Slip, anti-blocking, or rub-handling pressure: the finished surface needs better downstream handling.
- Recoating constraints: the first layer still has to work cleanly with the next layer or process step.
- Cleanability or marker resistance: some decorative or functional systems need easier maintenance in addition to basic appearance control.
How to choose the first additive route
| Observed varnish problem | Best first route | Why |
|---|---|---|
| Gloss inconsistency, rough laydown, or weak flow-out after acceptable coverage | Leveling additive | The main issue is film appearance, not spreading or pigment control |
| Poor spreading, weak substrate coverage, or unstable wetting behavior | Wetting additive | The first problem is how the varnish reaches and covers the surface |
| Persistent craters, orange peel, strong shrinkage pressure, or need for more slip | Fluor oppervlakte-actieve stof | The system needs a stronger surface-control route than basic wetting or leveling alone |
| Need for easy-clean behavior, marker wipe resistance, or stronger blocking resistance in the final varnish layer | Additief tegen graffiti | The decision is being driven by end-use maintenance and final-surface durability |
| Pigment flooding or color instability in the printed layer itself | Dispergeermiddel | The root issue is in the ink or pigment package, not the clear varnish surface |
CHLUMICRYL® routes that fit UV varnish surface-control work
1. LA-D559 when the main issue is leveling, wetting, and gloss in UV cure
CHLUMICRYL® LA-D559 is currently supported by Longchang as a polyether-modified polydimethylsiloxane with OH functional group for UV-uitharding. The product page states that it increases leveling, wetting, and gloss for paints and inks, which makes it a practical first route when the UV varnish already reaches the surface but still does not look commercially clean enough.
- Supported fit: UV-uitharding
- Supported decision logic: use when appearance, gloss, and surface laydown are the main bottlenecks
- Suggested addition range: 0.05% to 0.5%
2. WD-D547 or WD-D548 when the first problem is wetting, spreading, or recoating behavior
CHLUMICRYL® WD-D547 is supported for water-borne paint, solvent and solvent-free paint, and UV-cure paint. Longchang states that it most effectively reduces surface tension in water systems and gives wetting, spreading, anti-cratering, re-coating, defoaming, and leveling performance. That makes it useful when the UV varnish problem starts with unstable spread or coverage rather than only with final gloss.
CHLUMICRYL® WD-D548 is supported for water-borne paint and solvent-based paint and is positioned around surface-tension reduction, wetting, spreading, anti-cratering, re-coating, and leveling. Longchang also gives it a strong Dynamische oppervlaktespanning recommendation score, which is commercially relevant when buyers are screening difficult spread or fast-coverage behavior.
- WD-D547 suggested addition range: 0,1% tot 0,5%
- WD-D548 suggested addition range: 0.1% to 1.0%
3. FS-D8975BR, FS-D8950BR, and FS-D8980 when varnish compatibility, slip, and anti-cratering matter together
For many UV varnish projects, the strongest CHLUMICRYL® surface-control shortlist is the fluorine-surfactant branch because Longchang explicitly supports these products for UV-uitharding op basis van oplosmiddelen and repeatedly ties them to varnish compatibility.
CHLUMICRYL® FS-D8975BR is supported for solvent-based UV cure with good compatibility in varnish, good long-wave leveling, excellent anti-cratering, suitability for large-area spraying, and Slip rated strongly in the product recommendation block. The suggested addition range is 0.05% to 0.8%.
CHLUMICRYL® FS-D8950BR follows the same commercial logic with varnish compatibility, Nivellering op lange golf, anti-cratering, and suitability for large-area spraying, while giving buyers a parallel route at a different active-substance level. The suggested addition range is 0.1% to 1.0%.
CHLUMICRYL® FS-D8980 is also supported for solvent-based UV cure with good compatibility in varnish, good long-wave leveling, anti-orange-peel support, and strong Slip guidance. The suggested addition range is 0.05% to 0.8%.
4. FS-D9013R when silicone-free restrictions or recoating logic matter
CHLUMICRYL® FS-D9013R gives a narrower but commercially important route. Longchang supports it for UV-uitharding op basis van oplosmiddelen with good long-wave leveling, excellent anti-cratering, fast leveling speed, high temperature resistance, En recoating support. The product page also says it is often used as an anti-shrinkage additive in systems where silicone additives cannot be used.
That makes FS-D9013R a strong first comparison point for UV varnish or primer work where ordinary silicone-based logic is restricted. Longchang also adds an important limitation: it is useful in common UV primer anti-cratering work without affecting recoating, but should not be used in UV vacuum electroplating primer because it will affect recoating.
- Suggested addition range: 0.1% to 1.0%
5. AG-D9000 when the final varnish layer must also stay easier to clean
Some overprint or clear topcoat systems are not judged only by gloss and crater control. They are also judged by how the finished surface behaves in use. AG-D9000 is supported by Longchang for op basis van oplosmiddelen systems and is positioned around improved surface anti-graffiti and cleanability, improved water contact angle, excellent blocking resistance, marker-pen wiping resistance, hydrophobicity, and oleophobicity.
This is not the right first route for every UV varnish project, but it becomes commercially useful when the buyer is building a clear layer that also needs easier maintenance or marker-release behavior. Longchang also notes that compatibility should be evaluated before use in varnish and suggests dilution to 10% to 20% with xylene before addition.
- Suggested addition range: 0.5% to 3%
How buyers should narrow the shortlist
Start with the real failure, not the additive family name
A gloss problem, a spreading problem, and a crater problem may all show up on the same UV varnish line, but they do not deserve the same first additive trial.
Keep varnish compatibility and recoating visible
For UV varnishes and overprint systems, it is not enough that the first coated panel looks good. The additive still has to fit the downstream process. That is why Longchang’s supported recoating note on FS-D9013R matters.
Do not confuse slip with cleanability
FS-D8975BR and FS-D8980 are useful when slip and surface control matter inside varnish-compatible UV systems. AG-D9000 belongs earlier when easy-clean behavior, marker wipe resistance, or blocking resistance are part of the commercial target.
Use a short first screen
For most buyers, the cleanest first UV-varnish screen is one route from each logic bucket: LA-D559 for appearance, WD-D547 or WD-D548 for wetting, FS-D8975BR or FS-D8980 for varnish-compatible fluorine surface control, and AG-D9000 only when maintenance behavior matters too.
Recommended CHLUMICRYL® internal path
- Core overview: CHLUMICRYL® coating- en inktadditieven
- Leveling support page: How to Choose Leveling Additives for Coatings and Inks
- Wetting support page: How to Choose Wetting Additives for Coatings and Inks
- Fluorine support page: How to Choose Fluorine Surfactants for Surface Control in Coatings and Inks
- Easy-clean support page: How to Choose Anti-Graffiti Additives for Coatings
FAQ
What is the best first additive route when a UV varnish already covers well but still looks uneven?
Start with a leveling route such as LA-D559, because Longchang already supports it for UV cure with leveling, wetting, and gloss improvement.
When should I move from ordinary wetting or leveling to a fluorine surfactant?
Move earlier to a fluorine route when the varnish still shows persistent craters, orange peel, stronger shrinkage pressure, or a need for more slip and varnish-specific surface control.
Why are FS-D8975BR and FS-D8980 strong UV-varnish candidates?
Because Longchang explicitly supports both for solvent-based UV cure and repeatedly ties them to varnish compatibility, long-wave leveling, and slip-oriented surface-control work.
Is AG-D9000 only for graffiti-resistant industrial coatings?
No. It becomes relevant in UV varnish or overprint work whenever the final clear layer also needs better cleanability, marker wipe resistance, or stronger blocking resistance, as long as the solvent-based system and compatibility window fit.
Need help narrowing the UV varnish additive shortlist?
If your UV varnish or overprint system is limited by rough laydown, poor spread, persistent craters, slip demands, or final-surface maintenance targets, begin with the defect that matters most and compare the CHLUMICRYL® route that matches that defect first. That usually creates a faster buying path than mixing wetting, fluorine, leveling, and easy-clean additives into the same first trial.