"Luster" (On Glaze Decoration)
Metallic decorations are applied on glass, porcelain and tile products with Luster, which means "to shine" in Latin. Today, in addition to handmade ceramic manufacturers, decorated products are also produced industrially with Luster application under conditions suitable for mass production.
From past to present, various luster techniques have been derived for the application of luster, such as paste luster, in-glaze luster, resinate luster and evaporation luster. In luster application, precious metal compounds such as silver, platinum and gold are used to obtain the desired color.
What is Luster?
- They are metallic and organic mixed products developed to decorate ceramic and porcelain products obtained after glazed firing.
- It is also called overglaze firing or third firing.
- The recipe consisting of precious metals dissolved in oil and resin is applied to the surface under suitable conditions, and the organics removed from the surface after firing are replaced by the shining of the metals.
How is it Applied?
- Application is done using a brush.
- Some lusters may need to be adjusted to suit the brush and the product being applied to. For this, luster thinner and some oils (e.g., lavender oil) can be mixed.
Crafist Luster Application Steps:
- Always use gloves and a mask before starting the application.
- The surface to be applied must be cleaned with cellulose thinner to remove dust.
- During application, the luster can be thinned with cellulose thinner. The thinning may vary depending on the type of luster.
- Lustre Over Glaze decorative application is applied uniformly in a thin layer on the surface.
- Using natural bristle (or soft synthetic) brushes during decoration application provides a more homogeneous result.
- After application, clean your brush and store it in a way that you won't encounter any issues in your subsequent applications.
- Ventilate the area where luster is applied after application to remove the intense solvent released in the environment.
What is the Luster Firing Program?
- Example firing program:
- Step: Ramp up to 800°C in 5 hours.
- Step: Hold at 800°C for 15 minutes, then shut off.
- Control panels on ceramic kilns may vary. You can adjust the luster firing program to correspond to the example firing temperature.
What Should the Right Brush Be Like?
- The best results in luster application are achieved with brushes made of natural bristles. Alternatively, you can use soft synthetic brushes. Depending on the size of your application area, using brushes with fine bristles or pompons is suitable
How Should Leftover Luster be Stored?
- Luster containing solvent material should be stored in a cold environment (e.g., refrigerator) after use to prevent it from being affected by room temperature.
What are Application Errors ?
1. What happens if you apply thick luster?
- Luster application is applied homogeneously to the surface in a thin layer.
- Although the thicker luster application may create the perception that you will get more shine after firing, the result may be disappointing. Thick applications burn and darken because they cannot bond sufficiently with the glaze in the oven.
- When applying thick luster, matte results may be obtained in some types of luster.
2. What happens if you dilute luster too much?
- By diluting the luster too much, we may not be able to apply sufficient amount of metallic compound to the surface. As a result, you may encounter black or purple colored results on the applied surface.
- Choosing the right brush and applying in one go is very important. If you don't choose the right brush for the right application, you'll have to go over the gilding several times. Although this may give the impression that you have applied the gilding properly, the brush bristles will collect some gilding from the surface with each stroke. This allows openings at the furnace exit.
After applying with the Crafist Luster Application Steps, Crafist Lusters fired in the correct firing program are dishwasher-safe and resistant to mechanical factors.