How to Make Gold Lustre: The Short Version

If you’ve come here for the recipe rather than the story, this is the page for you.

Below is my current mixing method for a 10g batch of gold lustre, using a blend of two prepared gold compounds. The chemistry behind making those ingredients is covered in the full guide.

Want the background? Read My Gold Lustre Journey: The Full Version.

Before you start

This recipe uses the stock solutions described in the full recipe chapter. Their concentrations matter, so don’t substitute a different strength and expect the same result.

You’ll also need a suitable chemical workspace, extraction, appropriate protective equipment and safe handling arrangements for flammable solvents. Read the safety data sheets before working with the materials.

What goes in the bottle

• Gold compound prepared from butylbenzenethiol: 1.00g
• Gold compound prepared from dodecanethiol: 1.00g
• Toluene UV stock solution: 2.70g
• PMIB/rosin stock solution: 4.00g
• Bismuth stock solution: 5 drops in total
• Rhodium stock solution: 5 drops
• Additional solvent blend: enough to bring the finished batch to 10.00g

These are prepared gold compounds, not the raw thiols.

The drop quantities refer to my calibrated droppers, which deliver approximately 0.035g per drop. Check your own droppers first. Five drops from a different bottle may not be the same addition.

Mixing the lustre

1. Add the gold compounds

Start with a clean glass vial large enough to mix comfortably.

Weigh in 1g of the butylbenzenethiol-derived gold compound, followed by 1g of the dodecanethiol-derived gold compound.

This gives an equal-weight blend of the two prepared materials.

2. Add the solvent

Add 2.70g of your toluene UV stock solution and stir to dissolve the gold compounds.

The UV tracer makes the applied coating easier to see later. It’s useful when you’re trying to judge coverage on a surface where the wet lustre can otherwise be difficult to follow.

3. Add the first portion of bismuth

Add two or three drops of bismuth stock, slowly, while stirring.

Don’t tip the whole addition in at once. Bismuth can be a little touchy, and splitting the addition has worked well for me.

4. Add the binder stock

Add 4.00g of your PMIB/rosin stock solution.

Stir slowly until the mixture is uniform. This is the existing stock formulation; the rosin has not been reduced in this version.

5. Finish the bismuth addition

Add the remaining bismuth stock to bring the total to five drops.

If you added three drops earlier, add another two now.

6. Add the rhodium

Add five drops of rhodium stock, then mix thoroughly.

It’s a small addition, but small doesn’t mean optional.

7. Bring the batch to its final weight

Add your solvent blend until the complete batch weighs 10.00g.

With my drop sizes, this is approximately another 0.95g of solvent. Use the scales to reach the final weight rather than treating that estimate as an exact addition.

8. Mix and rest

My existing method uses gentle warming to around 30°C, with slow stirring for a few hours, followed by cooling and resting overnight.

Only use equipment and ventilation suitable for flammable solvents. No naked flames or improvised heating arrangements.

9. Test before committing

Try a small amount on a glazed test piece before putting it on anything precious.

Watch how it brushes, how it dries and how the fired film looks. The UV tracer should help you inspect the coating using a 365nm UV torch.

Keep a note of the glaze, application and firing conditions. A good result is much more useful when you know how to repeat it.

Why use two gold compounds?

My earlier formulation used the butylbenzenethiol-derived gold compound on its own.

I now blend it with an equal weight of the dodecanethiol-derived compound. The latter forms a waxy solid, and in my tests this has helped the applied film remain flexible as it dries, reducing its tendency to lift or crack.

The two prepared gold compounds make up 20% of the finished mixture by weight. The actual gold content is approximately 10%.

For pure, dry gold(I) thiolates, 1g of the butylbenzenethiol-derived compound contributes approximately 0.544g of gold, and 1g of the dodecanethiol-derived compound contributes approximately 0.494g. Together that gives about 1.038g of gold in a 10g batch, or 10.4% by weight. This is a theoretical figure; residual solvent or impurities will affect the actual content.

What about the rosin?

For now, it stays.

The blend appears to be doing some of the job I previously relied on rosin for, but I haven’t yet completed the tests needed to remove it from the published recipe.

My next batch will investigate removing the rosin, followed by experiments with lower polymer content. I’ll update this page when I have results, rather than ask you to follow an experiment I haven’t finished myself.

For stock preparation and the detailed chemistry, continue to the full gold lustre guide.