Orange Luster - intended for brush application onto fired and glazed surfaces. There are definitely important tips you need to know before working with Lustres

The ceramic lustres are organic compounds of precious metals and base metals offered in the form of finished paint which is applied over-glaze on glass, porcelain or ceramic. They are liquid and sometimes should be diluted with appropriate (thinner) diluent. Before firing, the objects must be left to dry for a few hours in a warm, dust-free place. Gold, Platinum, Copper, and Bronze do not need in general to be diluted.
Precious metals and lustres for ceramic decoration contain mixtures of gold, silver, platinum and palladium along with other trace metal additives.

How to use Lustres for ceramic:

Lusters are ready to use and are dark brown liquid aspect. Use a smooth brush. The products to be decorated must be cleaned and dry. The brush must neither be too heavily-laden nor too little-laden and the layer applied must be uniform and fine. Too thick a layer causes burning or clouding during the firing.
Metal lustres for ceramic decoration and of course orange lustre products such as resinates for industrial and electronics use have different firing range.