Tips for Selecting an Interior Wood Finish

A trio of paint brushes over cans of varnish.

When you’re decorating the interior of your home or working on a project, there are seemingly endless decisions to be made. And whenever you’re working with wood on an interior project, one of those decisions involves choosing the perfect stain or finish. While this question may seem straightforward, it can quickly become trickier than expected. Below, learn how to make the best decision on an interior wood finish to complement the aesthetic of your home.

Different Types of Finishes

Having a solid understanding of different types of finishes will help you to make the most educated decision on which finish is right within your home. Without further ado, here are the most popular and accessible types of finishes.

True Oils

A panel of wood being stained.

Linseed and tung oils are drying oils that are most frequently used for wood finishing. These are easy to come across and are also relatively inexpensive, which make them an attractive option. These are referred to as “true oils,” whereas other oils that are non-drying or semi-drying, such as soybean oil, are separate. Unlike non-drrying or semi-drying oils, true oils morph from a liquid to a solid through a process called polymerization. This strengthens the cured finish, making true oils reliable for interior wood pieces.

When it comes to linseed oil, the most commonly used variety of this substance has been boiled. Boiled linseed oil makes it thicker and able to dry more quickly. This is also referred to as heat-treated or polymerized oil. Often, linseed oil that is marketed this way is actually raw oil that has been mixed with chemical additives to speed up dry time.

On the other hand, tung oil is derived from the nuts of trees that originate in Asia, but nowadays are found in other parts of the world as well. This oil is often heat-treated, helping it to become more durable as a wood finish and speeding up drying time. This finish is paler in color and has a higher level of moisture resistance than other oil finishes, making it a desirable option.

Both of these so-called “true oil” finishes are penetrating, meaning that they penetrate the fibers of wood that they are applied to, and then harden. These are easy to apply; they only require to be wiped on, and then need to sit on the wood to give them the chance to penetrate. After that, they should be wiped with a rag to get rid of the excess.

Because these finishes dry slowly in cold or humid temperatures, they should be avoided if in an environment with either of these temperature factors and if the setting is dusty. Dust could fall onto the finish and end up drying within it if the temperature is not correct.

Varnishes

A man painting a wood panel with stain.

Another variety of interior wood finishes is varnishes, which are made of tough and durable synthetic resins that have been modified with drying oils. Varnishes, like true oils, utilize the polymerization process. However, the difference lies in the resins, which make them a more durable finish. Varnishes that have a high percentage of oil are referred to as long-oil varnishes. Short-oil varnishes, however, require high temperatures to dry, making them more suited for industrial applications.

Given its durability, varnishes are a highly desirable finish. Other factors that make varnishes a great pick are that they are practically unrivaled in their resistance to heat, water, solvents, and other chemicals. Varnishes are also easily applied, even by someone with little woodworking experience. Typically, varnishes are applied with a brush, although a wiping varnish, which is thinned and gelled, can be alternatively applied with a rag.

Water-Based Finishes

Staining a wood chair.

Another common type of interior wood finish is those that are water-based. These include similar ingredients to varnishes such as urethane, alkyd, and acrylic. These are less flammable, however, as some ingredients have been replaced with water. These substances have a more complex chemistry, as they must be modified to combine seamlessly with water.

These finishes are scratch-resistant and tough due to the presence of urethane within the resin, which makes them great for pieces that will see an abundance of traffic. However, these finishes do not have the same heat resistance that oil-based finishes do, so that’s something to keep in mind.

Matching a Finish to the Desired Aesthetic

Besides picking a finish that has the right durability and chemical properties to meet your needs and skill level, you’ll also want to choose a finish that matches the look you’re going for. For a natural looking finish, oil or varnish blends are the best option. These don’t form hard surface films and are easy to apply, making them a great choice, especially if they’re in line with your desired aesthetic.

If you’re aiming for a deeper finish, a hard, film-forming variety is more appropriate. This may include a varnish or shellac. These are also necessary options for projects where the finish is to include complex coloring or glazing.

Oil-based finishes and varnishes tend to deepen the color of wood and increase luster once applied to a piece of furniture or flooring. On the other hand, water-based finishes lie more on the surface instead of penetrating the wood, making the wood appear lighter in color.

Choosing the type of finish based on its individual properties, application process, and look may seem like an intimidating task, but really it’s a straightforward one when you do the appropriate research!