An Overview of the Decal Production Process

  • Jun 10, 2022
  • Category: Decals

Tags - Decal Production Process

If you're in the market for custom decals, you may be wondering what the production process looks like, or what technology is involved. 

To put it simply, a decal is a decorative method by which designs are first printed on a special paper pre-coated with water-soluble glue, then immersed in water, and then transferred to the surface of ceramic items. 

Whether it's mugs, plates or bowls, the process is the same. 

In this blog, we will give you a brief overview of the process involved to create high-quality, unique decals. 


3 Categories for Decal

The decal paper production can be divided into three categories: on-glaze colour, in-glaze colour, and under-glaze colour.


1. On-glaze Colour

The most popular, cheapest and most varied colour palette of the ceramic decal system.

Ceramic decals are applied to the glazed ceramic surface and fired in ranges of 800 – 900°C. 

The colours on the fired designs remained in place because the firing temperature did not reach the melting point of the glaze layer, and as a result, they were unable to sink into the glaze layer.


2. In-glaze Colour

In-glaze is applied when a higher durability ceramic decal product is required and is typically fired between 1100 and 1300°C. 

At this higher temperature the in-glaze ceramic decal sinks into the glaze providing higher resistance and a brighter surface.


3. Under-glaze Colour

With the under-glaze technique, the colours are decorated on the ceramic body and then glazed. 

After glazing, the products are twice fired at a high temperature to provide ultimate durability; the decal is placed onto the bisque plate and fired to harden, then the glaze is applied, and the product fired again to seal the decal completely. 

As a result of high firing temperature, the colours can easily diffuse, making it difficult to create complex designs. 

So the patterns used in under-glaze decoration, in general, are relatively simple.


Why Are Different Temperatures Required?

With firing temperatures ranging between 800 - 1300°C, the paper used is highly resistant, will not wear off even after a long time and the colours will remain bright. 

Depending on the colours and materials, different firing temperatures will be used. 

But this requires accuracy because if the firing temperature is too high, it's very easy to burn and the colours will not be as vibrant.  

If the firing temperature is too low, the decal will not stick to the surface or it may wear off quickly.


How Many Colours Can You Use?

For on-glaze and in-glaze decoration, an unlimited number of colours can be used because the decal is printed using a CMYK printer. 

This means that any colour you can imagine can be printed on the decal paper.

However, for under-glaze decoration, because the colours are applied manually one by one, only a limited number of colours can be used - usually no more than six.


The Durability of Decals

The durability of decals is largely dependent on the firing temperature. The lower the firing temperature, the shorter the lifespan of the decal. 

For example, if you use an on-glaze decal for dishware that will be used daily, it's advisable to choose a higher firing temperature to increase durability.

On the other hand, if you're using decals for non-food items like bathroom tiles, a lower firing temperature may be sufficient because the decal will not be exposed to water or other harsh chemicals.


The Bottom Line

As you can see, there's a lot that goes into the decal production process - from choosing the right paper to ensuring accuracy during firing. 

But when done correctly, the results can be stunning and long-lasting.


We hope you found this overview helpful. If you have any questions or would like to learn more about the decal production process, feel free to contact us

In the meantime, take a look at our range of decal services here. Thanks for reading!


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