Great interior design is in the details—details like that splash of silver, glint of gold, or glow of copper. Metals, whether they blend into the background or take center stage, can add style and warmth to a space. Best of all, they don’t even need to match. This means that the gleam of gold is welcome in practically any room. But that doesn’t mean it’s time to start replacing fixtures. A few well-chosen gilded accents can go a long way in adding elegance.

There’s no need to spend a lot on gold-finished items. Instead, get crafty at home and turn everyday objects like lamps, vases, bathroom fixtures, and bookends into beautiful, shimmering accent pieces. Adding a gold finish, or gilding, is an age-old technique that dates back thousands of years to the ancient Egyptians. They believed that gold was the color of the gods and often used gold leaf to adorn tombs as well as wood and metal objects.

Getting started with gold finishes isn’t as complicated as it might seem. Continue reading for ideas and techniques.

RELATED: The Best Gold Spray Paints

1. Spray Paint

Turn an everyday object into something special by applying metallic gold spray paint. A favorite among DIYers, Rust-Oleum offers several options, including its American Accents 2X Ultra Cover Metallic Spray Paint, which is a combined paint and primer for both indoor and outdoor projects, and its Metallic Gold Spray Paint, which incorporates real metal leafing flakes. Best of all, using spray paint to give small objects a lovely gold finish takes practically no time at all. Simply set up in a well-ventilated area, give the item a light spray of coverage, let it dry for 5 minutes, and apply a second coat. Note that faucets and other fixtures near water as well as high-use spots such as doorknobs will hold up best with a clear sealant. Also, before you try to transform bathroom fixtures, cabinet pulls, and other metal objects, bone up on how to spray paint metal.

RELATED: The Best Spray Paints for Your DIY Projects

2. Metallic Wax Finish

This crafter’s favorite metallic wax finish from Rub ’n Buff at Amazon can be used on just about any surface. A tiny bit will instantly breathe new life into tarnished knobs, vases, and lamps, or try it on desk legs for a gold-dipped look. Simply put a dab on a rag, rub it in, and watch the finish turn shiny. Multiple shades of gold are available, and a clear sealant can be added for high-traffic spots.

3. Imitation Gold Leaf Application/Gilding Kit

Ideal for small details such as the bottoms of glasses or parts of a statue, gold leaf gilding requires a bit more care than the previous options. The Speedball Mona Lisa gold leaf kit at Amazon comes with an adhesive, protective varnish and 25 sheets of imitation gold leaf made of copper and zinc. The gilding process involves cleaning the item, applying the adhesive with a brush, pressing in the gold leaf and refining it with an additional brush, and then finishing with the varnish.

4. Genuine Gold Leaf

Genuine gold leaf looks similar to imitation but is much more fragile to manipulate. Although more challenging to work with, it looks stunning on artwork and other small details around the home. Professional-grade Genuine Gold Leaf Sheets by Barnabas Blattgold are applied in the same way as an imitation gold leaf, albeit more carefully. The same manufacturer also sells gilding adhesive and a sealer for finishing off gold-leaf projects.

5. Gold Paper Decoupage

Decoupage is the process of gluing paper to an item using several layers of adhesive. It can be done on any surface, including wood, glass, plastic, metal, and fabric. Using metallic papers like this handmade vintage Lokta paper by MysticHimalaya at Etsy for decoupage is an excellent way to give home objects a golden flair. The process is fairly simple: Brush the surface with glue such as Mod Podge, add the paper, brush on more adhesive, and smooth with a firm flattening tool. This Mod Podge decoupage starter kit at Amazon comes with both glossy and matte finishes and three brushes.

RELATED: 7 Classic Decoupage Projects for the Home

6. Gold Mineral Paint

Mineral paint, as the name implies, uses natural minerals to achieve different shades. The color generally goes on smoothly without the need for a base primer. Wood surfaces, however, still need to be sanded down before application. Try a product like Fusion Mineral Paint at Amazon on furniture trim or a small wooden nightstand to create a beautiful gilded accent piece. Users love that this product is made without toxic chemicals and has low odor and VOCs.

RELATED: 11 Insanely Easy 60-Minute Paint DIYs

7. Acrylic Paint

Traditional acrylic paint can do the job too. Add a metallic sheen to decorative objects with water-based, nontoxic FolkArt Treasure Gold Paint, which reviewers on Amazon praise for its great coverage and shiny gold finish. Acrylic paint can be used on wood, canvas, paper, metal, terra cotta, and more so you can have fun with it on vases, frames, furniture trim, and all sorts of accessories. For knobs, pulls, and other high-use objects, make sure to apply a clear sealant.

RELATED: 9 Ways to Decorate With Your Crafts and Put Your Hobbies on Display

Contact paper like this gold self-adhesive contact paper at Amazon is a simple way to quickly transform plain surfaces with a metallic look. It comes in a roll similar to wallpaper and includes a self-adhesive film so it goes on super easily once the design or shape has been cut out. It’s great for covering smooth, flat surfaces and ideal for use on glass or painted surfaces.

RELATED: 13 Unexpected Ways to Use Contact Paper Around the House

9. Foil Transfers

Don’t forget to add golden touches to textiles as well. Throw blankets, pillows, and curtains are great places to start, and foil transfers like this Firefly Craft elastic heat transfer vinyl by FireflycraftStore at Etsy are an easy way to make it happen. Transfers work similarly to gold leaf sheets, except heat is needed for the transfer. The process used depends on the product you’re working with. Some transfers come mounted on a backing and have heat-activated adhesive, while others require applying adhesive separately. Either way, once the foil is in position, apply heat with an iron. Give it time to cool before peeling back the foil to reveal the finished design.

RELATED: The Best Heat Transfer Vinyl

10. Antiquing Gel

For a more aged, antique look, try a gold metallic antiquing gel from All-in-One Paint by Heirloom Traditions. It’s essentially a glaze with a built-in top coat. Unlike a glaze, however, the thick gel doesn’t drip. The gel comes with a brush and is applied like traditional paint, but it’s then rubbed with a dry cloth to create the antique gold look. It stays wet for 12 hours, so mistakes can be fixed by spraying the item with water and manipulating the paint to achieve the desired result.

Usually, most people who make some microwave stuff think that the best finish they can apply to their boards is gold. It looks good, doesn't change over time and since most HF (high frequency) energy flows through the surface due to the surface effect, it's best to have some protection on the copper traces. In this case, gold.

Some of these rules are right, some are OK and some are simply off.

Available finishes

First of all, let's list the usual finishes available from almost all manufacturers, even the Chinese ones:

• HAL (or HASL) - solder is applied to the whole board and then blown off using a very fast stream of hot air
• Leadless HAL - the same, just without lead
• ENIG (also called immersion gold or soft gold) - two-layer electroplated protection which contains nickel layer directly on the copper traces and thin layer of gold on the nickel layer

And now the less usual ones, or at least less used ones:

• Hard gold - almost the same as ENIG, but the layer of hard gold can be much thicker, its crystals can be about 50x smaller than when using soft gold and the gold usually contains nickel, cobalt or both to make it much harder
• OSP - organic protection which sticks to the copper and forms organometallic compounds which prevent oxidation, disappears during soldering
• Immersion tinning - electroplated tin
• No protection, simply just bare copper
• ENEPIG - ENIG with additional palladium layer which should prevent "black pads" which can form during electroplating and reduce solderability of the gold layer
• EPIG - just like ENIG, however nickel is left out and substituted by palladium
• Kapton solder mask - sometimes called generally Coverlay (trademark of DuPont)

Solderability

Now, let's mention the solderability of the more usual finishes, listed from best to worst:

1. HAL
2. Leadless HAL
3. ENIG
4. OSP
5. Bare copper
6. Coverlay
7. Immersion tinning
8. Hard gold

That may sound strange, doesn't it? You were probably expecting the gold finishes on the top places. And that's the first common myth. Gold isn't the best solderable finish. HAL is usually the best one.

Repeatability

This means repeatability of thickness, surface roughness, resistivity and how precisely it is controlled over the board:

1. Bare copper
2. Coverlay / OSP
3. ENIG/EPIG/ENEPIG
4. Immersion tinning
5. Hard gold
6. HAL / leadless HAL

Again, gold isn't the best one. Bare copper and its "covered" variants have the lowest tolerance, roughness and best repeatability. ENIG and its variants suffer from tolerances of the thick nickel layer which usually has rounded edges. For example, let's show an image. Its source is IEEE-Xplore. If you cannot open this because you do not have the magical paywall access, you can find this article on Z Library, just try to find its name. I won't be inserting link to Z Library, because I do not know how prudent HackaDay is when it comes to links to illegal sources of science...

As you can see, the trace is nowhere near the ideal rectangular shape everyone wants to see. If you look closely on the Cu trace, you can see the effects of etching. And the Au/Ni part makes the Cu trace more rounded and thicker than it should be, which is worth noting.

HAL isn't very well controlled process in this point of view. The lead dissolves partially the copper beneath and when blown off using the hot air, it is not very flat. Look at these two pictures.

As you can see, it is not flat at all. That's the main problem with HAL - nonpredictability.

HF performance

Now, let's list those finishes in order of suitability for microwave stuff:

1. Bare copper
2. Coverlay / OSP
3. HAL / leadless HAL
4. EPIG
5. Immersion tinning
6. ENIG/ENEPIG

OK, this is starting to be confusing. Why is ENIG never on the top? Why not even in the top 3? The answer is nickel. Maybe that was too short answer. Let's just state that copper or its covered variants have very low losses on microwaves if the copper is smooth. The reason is that rough surface increases the length of the trace virtually and that increases the losses. HAL is useable, but its impedance may slightly vary due toits non-flat surface. However, it is more or less smooth. EPIG is a bit worse, because the surface is "grainy", but OK. ENIG and ENEPIG are not very good because of its nickel layer and surface roughness.

Why is nickel such a b*tch?

Nickel is ferromagnetic. That means it does strange and not very pleasant stuff with microwaves. And what is even worse, it is not even consistent at doing so. The main problem is that its permeability drops quite fast between 2 and 3 GHz from 5.7 to something about 1.4. And it even shows off resonance in this frequency range. There is nothing you can make about this, this is a material property. Of course, you could make each trace shaped like a filter which would make the losses flat, but that would be difficult, take a lot of space and would increase losses over the whole used band.

Let's look at the losses of ENIG trace, again taken from the same article as before.

There is the resonance. As you can see, the steepness of the loss rise lowers above 3 GHz. That's because above this frequency, the nickel layer stops behaving as a proper ferromagnetic material.
The same happens for group delay which is where the researchers smelt something stinky about ENIG.
A resonance! And quite apparently visible. They tried to model the ENIG trace using Debye dispersion model which proved to be insufficient and so the used a mixed model constituting of the Debye dispersion model and Landau-Lifschitz's permability dispersion model. This way, they were able to model the resonance and both the losses and group delay. If they are speaking truth, they are the first ones to have ever done so. Let's look at the complex permeability of nickel in ENIG. Sorry for the utterly ugly Excel graph, it is taken from the article as-is.

As you can see, for a while, the permeability even drops under zero for a quite large frequency range. And since the permeability is mostly imaginary in this range, you can expect quite a lot of strange things happening, like a lot of losses and resonance in the losses.

As you can see, ENIG finished traces can have losses near 0.5 dB/cm at 2.5 GHz (sorry, I am not going to give you values in dB/inch, because inches are not measurement unit, but a heresy which has to be stopped).
That means if you have about 2 cm distance between the u.fl connector on your WiFi modem in your notebook and the transceiver, you are losing 1 dB of power. That may not sound like much, but this means 20% of power. That means about 11% loss in useable distance of the WiFi. Now, it doesn't sound like such a little problem, eh?
Of course, a lot of the losses is caused by the substrate losses, finite conductivity of copper, gold and nickel. However, the nickel layer causes a lot of trouble. Let's compare it with another research article. This time it will be this article. Let's first have a look at the surface finish in cross cut. As you can see, the top of the trace can be quite flat, however the bottom surface is quite rough. And this causes a lot of losses, too.

The ENIG losses are more than twice as large when compared to lead HAL, which means that if you make two reference traces made with both the HAL and ENIG and then another, longer one whoch would have twice as much loss with the HAL, the ENIG one would already have about five times larger losses. If you think about these numbers in these real-world scenarios, it looks quite scary. And even then, most microwave engineers use ENIG daily, because everyone does.

As you can see, it looks that OSP isn't that bad as you would probably expect.

There is another interesting article which has data up to 67 GHz. It even list one more not very usual finish, the ISIG or Immersion Silver Immersion Gold which looks to be really good. Does anyone know of any manufacturer which would make this finish?

That ISIG looks real good. As you can see, the losses per length are more than twice as large for ENIG than for bare copper. Coverlay is somewhere between and EPIG is quite near ISIG and bare copper. The renonace bump on losses in ENIG is not visible, however that could be due to scale, different manufacturing process, different nickel alloy used or the traces could be smoothed. At least they look suspiciously smooth to me. The paper mentions the ENIG losses look somewhat like square root of frequency up to about 15 GHz. In 1935, Landau and Lifchitz proposed a theory that the corner frequency for nickel would be around 15 GHz. Maybe they were right. However, the researchers behind this article have very weak theory on why these losses happen in nickel, even though they reference the article about the permability modeling. As if they even did not bother to read an article they reference.

Should I avoid using ENIG?

You know the rule for questions in headlines. This time, the answer is "depends on your usecase" and not exactly "no". To make a few simple rules:

I am making something that operates on units or tens of GHz. Analyze the losses for several different finishes and then choose the one which is the most suitable for you. It may be the best one or the cheapest one depending on your needs.

I need to make some microwave measuring device that has an over-the-top performance and cannot withstand any losses which are not necessary. ENIG and ENEPIG are out of choice. Don't use them. If you need to have each device consistent with each other and very precisely controlled impedance on traces, avoid HAL.

I want to make some microwave stuff, but want it to be super cheap while still useable. HAL is probably your choice. OSP or bare copper can be fine too, but cost usually more. Avoid ENIG as it drives the price up significantly.

I am making general microwave stuff which has no special needs. Choose whatever you like, anything is good enough for you.

I am making a sub-GHz circuit which won't have insanely long signal traces all over the board anever will make anything over the GHz mark. You didn't have to read this article. Sorry for your time.