Troubleshooting I Missing Gloss (draw back)

The challenges of missing gloss

Gloss is the ability of a surface to reflect light totally or partially. The more light is reflected, the more glossy the appearance of the surface. The contrast of gloss is matt. Also with regard to printed products, light is reflected depending on the type of surface. This means: The more even the surface, the stronger the reflection and the higher the gloss. If your surface is uneven, light is spreaded. The coating appears matt. Thus, the gloss of a coating is both dependent on the coating itself and the applied substrate. But also ink coverage and coating coverage play an important role. If you are facing – as sometimes possible – a draw back effect (the loss of gloss points), this may damage the quality of your printed products. Often, a draw back effect can be observed after 24 hours.

Solving missing gloss (draw back)

S​​tep by Step

1. Coat wet on dry

A gloss decrease can happen due to the penetration of coatings into the wet ink. Also, components of the printing ink can link with the coating. This effect mainly occurs during the inline varnishing on high ink coverage. Please ensure that inks are sufficiently dry.

2. Check your coating application

Also, the amount of your coating application can influence the gloss level. Please pay attention to our recommendations in the corresponding Technical Data Sheet.

3. Use a primer if possible

For UV coatings we recommend a waterbased primer for sealing the substrate’s surface. If you are using conventional inks and a UV coating inline, you need a double coating unit. The waterbased primer seals the surface; thus, the UV coating cannot absorb into the oil based inks. Important: Ensure the sufficient drying of your waterbased primer.

4. Choose another substrate

Use glossy coated substrates with a homogeneous and closed surface if possible. Avoid substrates with a rough coat. This will ensure that light can reflect in a better way, the gloss is increasing.

Your checklist

Influence factor: Coating (1)
Measure: Coat wet on dry

Influence factor: Coating application
Measure: Increase application amount, if necessary

Influence factor: Coating (2)
Measure: Use a primer, if necessary

Influence factor: Substrate
Measure: Apply an alternative with a homogeneous surface

Still have open questions? Contact us and we will support you with the application.

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