Paiting with Acrylics on Large Glass Windows, Doors and Panels
Unlike thinner paints that are water based such as Poster Paints that become runny and uneven in texture when using them on glass, Acrylic paints are a great choice instead. When working on a large glass surface such as a glass door, large french doors, window panels, large mirrors or store windows, Acrylics work great when it comes to preservation of texture, color and consistency. On a large glass surface, paint is often vulnerable once it has dried. It could be changes in the temperature or sun exposure that could cause cracking or flaking if thinner paints are used. As well, thinner paints tend to leak light and colors are less authentic. With Acrylics, there is a thicker consistency so light leakage is less likely which promotes better resolution especially if the painting is intended to withstand time.
One thing to remember is that Acrylics dry very fast. This is good in the fact it doesn't run like thinner paints, but because it dries so fast, if there is a need for blending or shading, it may dry too fast for the blending to look appropriate for transitional shading. A great tip is to add water to a desired effect so that the paint remains wet longer without becoming runny. Sometimes Acrylic will tend to become bubbly and almost look soapy when water is added to the paint. So when water is added, it's important to swirl the brush or foam tip through the paint at a slow enough pace to avoid bubbles from forming. It's important to note that Acrylics come in both oil based and water based varieties.
Especially when working on glass, Acrylics stay true to color and consistency which means, once a layer is painted on the surface of the glass, that is the color and image that will appear on the other side. If you plan to blend colors, add shading, or other things on top of the bottom layer that has already been applied to the glass, it will not be visible on the other side of the glass if the bottom layer has already dried. So, have a game plan ready on your color and design before you apply your first layer or coat. The best way to do that is to have a large paint mixing board or tray ready with all the shades you'll be using and use that to pre-mix your shades so when you apply them to the glass, they will have a smooth and natural transition that appears on both sides.
A fun aspect to layering is to apply a coat of paint to the glass and wait until it has dried. Then, take a razor blade, a large needle or even Philips head screwdriver and use it as a tool to lightly scrape shapes, lines, and textures into the dried paint to create a new space on the glass that can be painted over that will really stand out on the other side of the glass. This can actually create an optical illusion of stained glass in which the design can be filled in with white, black or brown to make the image appear as small glass tiles.
Layering with Single Colors
A creative way to add dimension and depth while keeping the color palette simple, is to use a single color or even just two colors with the same pattern and shape but layering them on top of each other. For example, use a simple leaf shape, circles, swishes or vines and create multiple layers. Paint a layer of leaf shapes. Let it dry and then do another layer in different places but overlap some of them. Do it again for as many layers as you want. The areas that end up overlapping will appear darker due to less light that is able to penetrate the paint.
The fun part of painting with Acrylics is that it maintains textures once it dries so whatever type of texture you want to create, especially with layering, it will maintain its shape and form. You can use stencils, screens, cut outs that can be dipped in the paint and applied to the glass or faux wall paint sponges and brushes. There are a large variety of choices that can be used. Even a crumpled washcloth can be dipped in paint and used to splotch paint on the glass.
Depending on how thick the paint is, it's still fairly easy to remove if you are painting on doors, windows or glass that you want to paint over or have clear and open. Using a bucket of warm water and large sponge works great to soften the paint but another tip is that the paint will often peel right off the glass with a little nudge. You can also use a window cleaner in addition to water. You can gently use a razor blade to scrape the paint and lift up under the thick layers and once a little bit has been lifted from the glass, you can grab it and peel more away. It's best to have newspapers or a drop cloth at the base of your work surface while painting and during clean up to ensure a mess free space.