A Comprehensive Guide to Glazing Utilitarian Ware using a Liner Glaze.

When it comes to creating pottery and ceramics, glazes play a vital role in enhancing the visual appeal of the final product. However, it is crucial to be aware of the potential risks associated with glazes, particularly in relation to food safety.

In this educational piece, we will explore the importance of using a ‘liner glaze’ for utilitarian ware.

When designing glazes for ceramics to be used for domestic purposes it is best to choose a plain gloss or white glaze.

This is because other additives, namely colorants, often consist of raw metal oxides. These are mainly used in small quantities but there is always a risk that they may leach into your food.

Now there is no actual evidence that these will cause you harm but if you wish to err on the side of caution and cut out the risk altogether then sticking with the principle of using a transparent or white ‘liner glaze’ is probably best for you.

There is a lot of information about pottery and a ‘liner glaze’ on the internet (DigitalFire, Ceramic Arts Network, and an array of forums). Many glaze suppliers also will sell certain glazes as ‘Liner Glazes’.

The term ’liner glaze’ refers to two things:

1. It is a technique, where the inside and outside of a piece have different glazes that meet at the rim.
2. It is the practice of choosing a glaze for the inside of utilitarian ware based more on its durability and resistance to leaching than for aesthetics.

A brilliant glossy white or transparent glaze are the most common ‘liner glaze’. The use of these will avoid releasing in-glaze or
on-glaze metallic colourants to food or drink (which could leach them away and be a health hazard).

Matte glazes can also be used as liners, but special effort and expertise are needed to produce a matte surface that is still silky enough to resist cutlery marking and staining.