Keum Boo is a traditional Korean jewellery technique where thin sheets of pure 24 carat gold are fused onto fine silver using a combination of heat and pressure. The name literally means 'attached gold'. The result is a permanent metallurgical bond that creates a durable layer of gold around 14 microns thick, which is six times thicker than gold vermeil.

How does Keum Boo work?

When fine silver and 24ct gold are heated to 260-370°C (500-700°F), the atoms at the surface have enough energy to start moving and interacting. When you press the gold foil firmly onto the silver at that temperature, the atoms at the interface begin to diffuse into each other, creating a solid state diffusion bond. This creates a true metallurgical bond between the gold and silver, not just a surface attachment.

What tools do you need for Keum Boo?

To get started with Keum Boo you need: a hotplate that can hold steady high temperature, a polished agate burnisher, fine tweezers, heat resistant gloves, small scissors or craft knife, fine silver or depletion gilded sterling silver, and 24ct Keum Boo gold foil (not decorative gold leaf, which is too thin).

Can you use Keum Boo on sterling silver?

Yes, but you must first prepare the sterling silver through a process called depletion gilding. Standard sterling silver is 92.5% silver and 7.5% copper. The copper oxidises when heated and prevents proper bonding. Depletion gilding involves heating and pickling the sterling silver around 7 times to remove copper from the surface, leaving a thin outer layer close to fine silver that allows Keum Boo to bond properly.

What is the difference between Keum Boo foil and gold leaf?

Keum Boo foil is much thicker than decorative gold leaf and is specifically made for jewellery. Decorative gold leaf is far too thin and fragile for the Keum Boo technique. You must use proper 24ct Keum Boo foil to achieve a successful permanent bond with silver.

What are common Keum Boo mistakes to avoid?

Common mistakes include: using gold leaf instead of Keum Boo foil, working at the wrong temperature (too cool and the gold won't bond, too hot and you'll overheat the surface), skipping depletion gilding on sterling silver, and not protecting yourself from heat with leather gloves or heat resistant tools.

What Is Keum Boo? A Simple Guide to Adding Real Gold to Your Silver Jewellery

If you would love to add real gold to your silver jewellery, but working in solid gold feels intimidating or expensive, Keum Boo might be the perfect technique for you.

Keum Boo is a beautiful and more budget friendly way to incorporate 24ct gold into your work and elevate the silver pieces you are already making. In this guide, we will look at what Keum Boo is, how it works, what tools you need, and common mistakes to avoid, so you can try it with confidence.

*The Keum Boo Shell Necklace Online Project* *- turn real shells into solid silver and gold necklaces.*

What is Keum Boo?

Keum Boo is a traditional Korean jewellery technique. The name literally means “attached gold”. Thin sheets of pure gold, usually 24 carat, sometimes 23.5, are fused onto fine silver using a combination of heat and pressure.

The result is a permanent bond. You get a durable layer of gold of around 14 microns that will not rub off like some flash plating, and is around six times thicker than gold vermeil at 2.5 microns.

Keum Boo gives your pieces an elegant contrast between bright silver and warm gold, and it works especially well on textured designs and nature inspired jewellery such as shells, leaves, botanical patterns, and organic surfaces.

*Attaching Keum Boo foil to a fine silver sycamore seed earring using a hotplate, an agate burnisher and a pair of tweezers*

How Does the Keum Boo Technique Work?

Both fine silver and 24ct gold are very pure metals. When heated to the right temperature, usually around 260–370°C (500–700°F), the atoms at the surface have enough energy to start moving and interacting more.

At that temperature, if you press the gold foil firmly onto the silver, the atoms at the interface begin to diffuse into each other. On a microscopic level, the gold and silver are forming a shared layer, creating what is called a solid state diffusion bond.

That is what makes Keum Boo so special. You are not just gluing gold on top, you are creating a true metallurgical bond between the gold and silver.

*The good news is that you don’t need a lot to get started with Keum Boo*

What You Need to Get Started with Keum Boo

You do not need a huge amount of equipment to try Keum Boo jewellery at home. Before you start, make sure you have:

A hotplate that can hold a steady, fairly high temperature
A polished agate burnisher to press the gold into the silver
Fine tweezers to place the gold foil
Another pair of tweezers or tongs to hold the piece in place while you burnish
Small scissors or a craft knife to cut your gold shapes
Leather or heat resistant gloves, because the hotplate and your piece get very hot
Fine silver or depletion gilded sterling silver, and some 24ct Keum Boo gold foil

Keum Boo foil is much thicker than decorative gold leaf, so make sure you are using foil specifically made for jewellery and Keum Boo. Decorative leaf is far too thin and fragile.

Shop the Keum Boo tools and foil via our Master Tools Lists:

*Depletion gilding a sheet of sterling silver ready for keum boo*

Using Keum Boo on Sterling Silver: Depletion Gilding

Keum Boo works beautifully on fine silver (99.9% pure silver). Standard sterling silver, however, is an alloy of 92.5% silver and 7.5% other metals, usually copper.

The copper is great for strength, but it oxidises when heated and gets in the way of the diffusion between the gold and silver that is required for Keum Boo to work.

To solve this, you can use a simple, slightly repetitive technique called depletion gilding:

Place your sterling silver on a soldering block and use your blowtorch to heat it until the surface oxidises.
Quench and pickle to remove the copper oxides.
Once clean, repeat this process several times. Each cycle pulls a little more copper away from the surface, leaving a very thin outer layer that is much closer to fine silver.

I usually recommend around 7 rounds. You will know when it is ready, because there will be no visible oxidisation when heating, and the silver will have a white, frosty appearance.

With fine silver sheet or fine silver clay, you do not need to do this at all, because it is already pure enough for Keum Boo.

Why Use Keum Boo in Your Jewellery Making?

What I love most about Keum Boo is its accessibility. While it does require practice and patience, the basic technique is achievable for jewellers at almost any level.

Keum Boo is ideal if you want to:

Add real 24ct gold to your work without the cost of solid gold
Create high contrast, nature inspired designs with warm gold highlights
Offer pieces that feel more luxurious and high end
Connect with a centuries old metalsmithing tradition while still working in a modern, creative way

It is a great way to elevate your silver jewellery and develop your design style.

*Adding a 24ct gold keum boo edge to a fine silver shell pendant*

Step by Step: How to Do Keum Boo

Here is a simple Keum Boo method you can follow once your silver is prepared and your hotplate is up to temperature:

Step 1: Cut your gold foil shapes
Cut the 24ct Keum Boo foil into the shapes you want to use. Simple leaves, dots, lines, or botanical motifs work beautifully.

Step 2: Heat your silver on the hotplate
Place the silver onto the hotplate and let it come up to temperature for a minute or two. You want it hot enough for the gold to bond, but not so hot that you overheat the surface.

Step 3: Place the gold foil
Use fine tweezers to carefully place the cut pieces of gold foil onto the hot silver. Once the foil touches the surface, it will start to stick lightly in place.

Step 4: Burnish to fuse the gold and silver
Use an agate burnisher to press the gold into the silver, using a firm, even pressure and keeping the burnisher moving across the gold until it has completely fused and does not peel or flake.

Step 5: Cool your piece
Once the foil is fully fused, remove the piece from the hotplate and let everything cool before handling it without gloves.

*Two shell necklaces with keum boo detailing along the edge*

Common Keum Boo Mistakes (and How to Avoid Them)

To get consistent results with Keum Boo jewellery, watch out for these common mistakes:

1. Using gold leaf instead of Keum Boo foil
Decorative gold leaf is far too thin and fragile. You need proper 24ct Keum Boo foil made specifically for jewellery.

2. Working at the wrong temperature
If the metal is too cool, the gold will not bond properly. If it is too hot, you can overheat the surface. Take your time to find that sweet spot where the foil “grabs” and bonds cleanly.

3. Skipping depletion gilding on sterling silver
If you try Keum Boo on untreated sterling silver, the foil will not bond correctly. Always depletion gild your sterling first, or work in fine silver.

4. Not protecting yourself from heat
Remember, the hotplate and metal get extremely hot. Always use leather gloves or heat resistant tools to move your plate and your piece.

Avoiding these will make your Keum Boo results much more consistent, enjoyable, and professional looking.

Ready to make nature-inspired jewellery one beautiful project at a time?

If you are excited to try Keum Boo and expand your jewellery making skills, I would love to help you go deeper.

Inside our Membership, you will find:

Our new step-by-step Keum Boo Shell Necklace project you can follow at your own pace
A new nature-inspired online jewellery project every month
A supportive community of makers to share your progress with
Ongoing guidance to help you build your skills and confidence, one beautiful project at a time

Learn how to make nature inspired jewellery online with the Cognac Jewellery School Membership

Click here to join now