Oil Painting on Glass: How to Prep and Seal

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Many people ask me if it is possible to paint glass items with oil paint. While there are many surfaces that oil paint doesn’t work well on, glass is not one of them. 

Can You Use Oil Paint on Glass?

Yes, you can use oil paint on glass. Glass is a great surface for oil painting. I will share the exact process of how to do it properly below.

Oil paints are obviously oil-based, so they glide smoother than other types of paint. This can present a problem when working on glass because its surface is also pretty slick. But, this doesn’t mean that oil paints can’t be used on glass.

You can very effectively decorate glass surfaces with oil paints, as long as you do it properly. That is what we are going to talk about today.

Keep reading to learn how to use oil paints on glass and more painting on glass tips.

How to Oil Paint on Glass

There are several steps involved in the process of oil painting on mirror and glass. As long as you follow all of these steps, your finished product should be a hand-painted decorative item that you can be quite proud of.

#1. Clean the Glass

Before you can start oil painting on glass, you need to clean the glass. This involves washing it with warm, soapy water to get rid of dirt, grease, and dust.

Rinse the glass with warm water, and allow it to air-dry completely. Once the glass is dry, put a bit of white vinegar or rubbing alcohol on a piece of paper towel and wipe the glass to get rid of any soap residue. Allow the glass to air-dry for about half an hour.

#2. Prep the Glass

There are two ways that you can prep glass for oil painting: use sandpaper or use a paint primer. If you use sandpaper, be sure that it has a very fine grit.

The only texture you need will come from the oil paint. It doesn’t need to come from the sandpaper. When you use sandpaper there will be just enough texture for the paint to adhere to the glass, but the glass will remain somewhat translucent.

When sanding glass, make sure that you always wear a respirator mask and safety goggles. There will be a lot of dust that could get into your eyes or affect your respiratory system. It is also a good idea to work outside, at least for this part of the process.

You can also use a primer to prep glass before applying oil paint. Gesso is an awesome primer, and it works very well on glass as well as most other surfaces.

The only problem with using Gesso is that it is usually white. This means that your glass will no longer be clear. Of course, there is such a thing as clear gesso, and I recommend using this for priming glass for painting projects.

#3. Start Painting

Once you have finished prepping the glass you can begin painting. Check these simple oil painting ideas if you need some inspiration.

When using oil paints on glass, always follow the fat over lean principle. Each layer of paint should be fatter (oilier) than the previous layer.

This is going to prevent the paint from cracking and peeling over time after it dries. This is common when using oil paint on glass, so use this principle to keep it from happening.

Basically, the thinnest layers of paint should be the first layers, and each layer will be thicker as you go.

#4. Seal Your Work

Once you have finished the painting and the oil paint feels dry to the touch (this could take a couple of days) you will want to seal the painting with varnish. 

When it comes to how to seal an oil painting, I suggest using a clear, spray varnish that will seal the paint without compromising the translucency of the glass.

Look for instructions on the label before you begin varnishing the piece. Also, make sure you are working in a well-ventilated area because the varnish has a pretty powerful odor. If you are anything like me, that odor can affect your breathing.

When applying spray varnish, be sure to hold the can about 12 inches from the surface of the glass. Spray the varnish in a slow and steady manner, moving your hand back and forth across the painted design.

To ensure that the seal is even, never spray in one area for too long. Once you have applied one layer of varnish, allow it to dry for about 15 minutes.

Repeat the process a few times, and then allow the finished piece to air-dry for about 24 to 36 hours.

Reverse Oil Painting on Glass Tips

Reverse oil painting on glass, also known as reverse glass painting, is a unique technique where the painting is created on the backside of a glass surface.

This process involves applying layers of oil paint in reverse order, starting with the foreground and building up to the background.

Here are the steps to create a reverse oil painting on glass:

Clean and prepare the glass

Clean the glass surface thoroughly to eliminate any dirt or debris. Before continuing, make sure the surface is totally dry.

Plan the design

You need to choose the composition and design of your artwork. Remember that the image will be viewed backwards through the glass, so paint the background first, followed by the foreground elements.

Paint the background

Begin by using oil paint to apply the background colors and components. Begin with the distant elements and work your way to the foreground. Always work in reverse order.

Add details

After the background has dried, begin painting the midground and foreground objects, adding finer details and highlights as you go. To get the required effects, use brushes of varied sizes.

Let it dry

Because oil paint takes time to dry, be patient and let each layer dry completely before adding further coats or details. Follow the manufacturer’s drying time recommendations.

Seal and protect the painting

Applying an oil painting-specific layer of varnish after the painting has completely dried will protect it. By doing so, the artwork will seem better overall and the colors will be preserved.

Reverse oil painting on glass requires a careful approach, as mistakes are not easily corrected. Take your time, plan your design, and enjoy the unique process of creating a painting that will be viewed in reverse through the glass surface.

Display Your Art Proudly

Once you have finished painting on the glass piece, you will want to display it proudly. You worked hard to do a great job, and you will want everyone to take notice of your work.

Make sure that you do not display the piece until it is completely dry. Otherwise, it could end up getting dust particles on it, which will attach themselves to the paint and stay there forever.

After allowing the varnish to dry, place the piece inside an airtight container for a day or two. This will ensure that it is completely dried and ready to display.

If you do oil paint on a mirror, make sure you have a proper holder to display your artwork, just in case it might fall and break.


Oil painting on glass is fun and relatively easy, as long as you follow all of the steps. As I already mentioned, be sure to wear the proper safety gear when working with varnish, and even with oil paints.

There are a lot of harsh fumes to deal with, and even if you don’t have respiratory issues or environmental allergies you still may find these fumes hard to deal with.

You should also wear rubber gloves to avoid getting any of the varnish on your skin. Some people are very sensitive to the chemicals in varnish, and you don’t want to end up with a bad rash.

Check my guides on how to paint on glass bottles and easy glass painting ideas for more tips.

*image by rinderart/depositphotos