The most common types of glass for stained glass are transparent, opalescent and opaque. Each type is used to create a different look or effect. It is common for a piece to only contain different colors and textures of one type of glass to create the image.
Transparent glass for stained glass can be clear or colored and can have a smooth or textured surface. It is also often referred to as cathedral glass because it is the most common type of glass used in the stained glass mosaics and windows of large cathedrals. It is made so that light will shine through and people can actually look through the glass. There are many types of textures available for varying effects.
Translucent glass is semi-opaque, usually with a mix or swirl of colors for interest. The way the colors are combined in the glass creates a swirl, cloud, or streak pattern, which can be used to simulate sky, water and more. This type of glass is also referred to as wispy glass. Generally, it is very hard to see through the glass, but light shines through freely to illuminate the design.
Opalescent glass is very similar to translucent glass in that the colors can be swirled together. It is also possible, though, to get opalescent glass for stained glass, which is one solid color. It is primarily associated with American stained glass art and is not transparent or see-through at all. Light shines through this glass, but in a diffused way to give the design a soft glow.
Opaque glass is generally available in solid colors. This glass is not transparent at all, and almost no light can shine through it. It is sometimes used in stained glass designs to create negative space, but is generally more popular in mosaics on backboards or even laid in cement or plaster.
Choosing the right types of glass for stained glass depends largely on artistic taste and the type of look the artist wants for his or her piece. If the desire is for bright and dramatic designs, transparent or cathedral glass generally works well. Translucent and opalescent glass create a softer, more diffused glow for a piece and comes in the largest variety of color combinations. Opaque glass is generally not suitable for any design which is made for light to pass through, but can create very vibrant mosaics. It’s often said that the best way to learn which types of glass you like most is simply to try them out.