Understanding your Glass

March 5th, 2021

A good craftsman is one who understands the materials of their trade inside and out. The same can be said about working with stained glass. Before you go cutting and breaking apart glass to work with, it helps to know about how it’s formed and the various types that exist.

For the most part, stained glass is typically created when a mix of sand, ash, metal oxide colorings, and other ingredients are heated to incredibly high temperatures to create a molten liquid. The liquid is then either blown or rolled into a thin sheet and left to cool. This process was originally done by hand, but can now be replicated with the help of machinery. One thing to note is that both techniques can result in various changes to the glass, such as its appearance, texture, and price.

Within the stained glass community, there are typically two categories of glass: Cathedral and Opalescents.

This sheet of Cathedral glass contains small ripples and bubbles that gives one side and added texture

Cathedral glass is transparent, meaning light can pass through it easily. Because of this, it’s often used in projects designed to be backlit by the sun. Cathedral glass panes are great for beginners because, not only are they made in a variety of different colors and textures, they’re fairly easy to cut.

This Opalescent piece has a wispy pattern that was created during the melting process

Opalesents have a milky, dense quality to them. As a result, light has a harder time transmitting through the glass. Most Opalesents are considered semi-translucent, meaning they allow some lite to pass through it, while some are virtually opaque and allow no light to penetrate at all.

Within these two categories of stained glass are subcategories, such as Antique, Iridescent, and Art glass.

Antique glass gets its name not because of its age, but from the traditional way it’s produced. When the glass is melted into a molten liquid, it’s then blown into thin sheets and allowed to cool. Because this process is more labor-intensive, Antique glass can be a little more expensive to buy.

You can see a little bit of shimmer on the surface of the Iridescent glass when the light hits it at just the right angle

Iridescent glass is created by adding metallic elements that are then fused with the glass itself. This results in an additional sparkling or shimmering effect.

The Cathedral glass is in the upper left corner while the rest is Opalescent

Art glass is unique in that it can have characteristics of both Cathedral and Opalescent glass. Due to the glass’ higher quality, it’s typically more expensive than other mass-produced glasses.

With all the different choices out there, choosing what glass to buy can seem daunting at first. For anyone new to stained glass, I would recommend buying Cathedral glass to start out. Not only is it generally the cheapest of the two categories, its also easier to cut. After you get more comfortable with cutting glass, then you can move onto other sub-categories.

There’s one last thing to always keep in mind when picking out stained glass: What glass you choose to buy all depends on the kind of project you’re working on. Consider where it will be presented; Is it meant to be hung on a wall or a window? How does the glass look with or without light piercing through? Does the glass complement/work well with other sheets your using?

Let me give you an example of just how much of a difference light can make glass look:

Here we have an Opalescent piece of red glass. As you can see, it has some wispy patterning to it, but for the most part the color is pretty consistent when light is piercing through.

Now here’s that same piece of Opalescent glass without light shining through it. Looks entirely different, right? In this image, you’re able to see the different patterns and colors of the glass that were impossible to make out before.

Keep all this in mind when perusing through stained glass your looking to buy for your next project!


One Response to “Understanding your Glass”

  1. Megan Rakow on March 8, 2021 6:27 pm

    I really enjoyed seeing the different types of glass and how light can affect them all in different ways.