In plain terms, opacity refers to the ability to see through an object or how much light comes through a material. When discussing the opacity of acrylic, a good way to keep this straight is comparing clear and black acrylic.
Clear cast acrylic is 0% opaque. You can see right through it. Clear acrylic is highly transparent and not at all opaque.
Black matte acrylic is 100% opaque. If you stood before a door made from black acrylic, you would not be able to see through it. It’s not at all transparent.
With opaque colored acrylic you will not be able to see through the material, but you often have varying degrees of light transmission, and the ability to see shadows.
The lower the degree, the less light travels through. The higher the degree, the more light travels through.
With many projects or repairs involving the need for illumination or privacy, opaque acrylic comes in handy. White and ivory acrylics are all commonly used to replace light source covers, privacy glass, as well as to repair light-up signs and backlight custom cabinets with LED strips.
As such, some very common and natural questions are:
“Will I be able to see the light bulb if I use this?”
In short, no. Provided there is space between the acrylic and the light source, you should only have illumination without seeing the source. If the light source is pressed up against the acrylic, you will be able to see it’s outline.
“Will I be able to see through this?”
On its own, you will not be able to see through the material. If there is a light source and an object close, you will be able to see its shape and outline, but no clearly defined features.
"What does nearly opaque mean?"
Since opaque acrylics have varying degrees of light transmission, they are not truly opaque. They are very nearly opaque!
"What acrylic is the most opaque?
Definitely check out the black opaque!
"How do I know what the light transmission is for each color?"
Check out the product descriptions for light transmission percentages!