Lighting fixtures can be an expensive investment for any home or business. It is important to choose the right lighting fixture that fits your needs, but it is also important to make sure you are purchasing a high-quality product. Because lighting fixtures are often used in highly visible areas of a home or business, poor-quality fixtures can make an entire space look cheap. The quality of glass is a factor that you should consider when making your purchase. Luckily there are some easy ways to judge the quality of the glass:

glass blowing process
light fixture glass blowing process

Glass Dimensions and Assembly

Does the glass size meet the requirements? The first step to judging a lighting fixture’s quality is to ensure that its dimensions are correct. Is it too small or too large for your space? You should also determine whether or not the glass has been cut properly and whether or not there are any scratches on it.

Is the assembly smooth and free of looseness? Next, inspect how well the fixture itself is assembled. There should be no gaps between parts, as this indicates poor workmanship in production. It’s also important to look for loose screws that may fall out during installation or down the road – this could cause damage if allowed to happen at home! Finally, pay attention to how smoothly each part moves as you move it around manually; this will tell you if they were assembled carefully using high-quality materials such as stainless steel screws instead of regular ones made out of cheap plastic material.


Evenness is the most important part of the glass that affects the appearance of a lamp and is the uniformity of the glass throughout its thickness. It is measured as deviation from an ideal surface. In other words, it is how much variation there is in roughness within a certain area. If two pieces of cut glass were placed side by side and examined under a microscope, one piece would reflect light with more evenness than another piece due to microscopic bumps on its surface. This uneven reflection produces streaks or spots called “striae” (singular stria) on both sides of your lampshade or shade when it’s lit at night from within your room.

If we use a high-resolution camera to zoom in on these shades at different magnifications you’ll notice that there are many fine lines/seams running through each shade which become apparent when viewed closely enough.

The best way to find out if a glass surface is even is to look at it from multiple angles under different lighting conditions. If you can see streaks, bubbles, or other imperfections on the surface from any angle, then it’s not evenly polished and may not be up to par for use in your home or business.

glass quality of lighting fixtures

Tonsda Lighting Glass

judge the glass quality of lighting fixtures

Tonsda Lighting Glass


Transmittance is the percentage of light that passes through the glass and into your home, which refers to how much light passes through the glass. The higher the transmittance, the more light will pass through. The lower the transmittance, the less light will pass through. To test for transmittance, we recommend using a tint meter. You can buy one at any hardware store or online, but if you don’t have access to one, here’s a simple way to approximate it:

  • When looking at a lamp or chandelier with clear glass, you can see how much light passes through by holding it up to a light source. If there is no glare on your hand, then this means that the glass has a high transmittance and it is likely an excellent quality piece of lighting equipment. If there is glare then this means that there is less light passing through and therefore it may not be as good quality as you originally thought.

Glass with high light transmittance allows more light to diffuse out, you’ll need fewer lumens to get the same effect. This means you’ll save money on energy bills, and your bulbs will last longer because they’re not working as hard to give off light. It’s important to choose lighting fixtures with a high light transmittance if you want to save money on your electricity bill and keep your lights from burning out sooner than they have to.


When looking at the exterior of the glass, be sure to check for any imperfections. Check for bubbles, scratches, or other imperfections on the surface of the glass. It is common for a slight defect in an exterior piece of glass to occur due to its manufacturing process and can be considered normal. However, if there are numerous defects on your piece of lighting fixture’s exterior then it may indicate that it wasn’t made with quality materials or that you have purchased a “seconds” item (which means it was not up to par).

For example, according to Tonsda Lighting’s standards, it is unacceptable to have air bubbles longer than 0.5mm in the glass, and such products will not appear in your purchase. If you have higher requirements for glass quality, please contact us for customization, and we can make a sample for your test and further evaluation.

glass quality - Tonsda Lighting

Tonsda Lighting Glass

judge the glass quality - Tonsda Lighting

Tonsda Lighting Glass

Shock Detection

Another step in judging the quality of a lighting fixture is to look at its shock resistance. This is a measure of how much force it takes to break the glass. There are two simple ways to judge the quality of a glass fixture:

  • Shock detection is the more reliable method, but it requires certain equipment, such as a hammer or mallet and a piece of wood with a notch cut into it. This method involves tapping the glass with the hammer and listening for a ringing sound; if there is no ringing sound, then this indicates that the glass is of poor quality.
  • The second way, drop that light on the floor from about 2 feet (61cm) above it. It should bounce off without breaking. If it’s not bouncing back up at all or if it’s breaking into pieces as soon as it hits the ground, then there’s something wrong with its shock resistance!


As you can see, there are a lot of things to consider when choosing lighting fixtures for your space or business. In addition to aesthetic factors like color and style, you also need to think about the quality of the glass and how well it will hold up over time. It is important to remember that what looks good in showroom conditions might not look so great in your own space! Make sure involves an inspection before purchasing so that you don’t end up with something subpar or worse yet damaged on delivery day.