Glass And Plastic Chair Mats: Choose Carefully
Chair mats can shave a large impact on your desk experience. Having a chair mat is great when you have the right one. Get the wrong one, however, and you end up wishing you never had one in the first place. Most mats are made from either tempered glass or a plastic (or vinyl) material, and what you get depends on a few issues. You'll want the correct type for the flooring you have, and the edges play a role in your comfort with using the mat, too.
Stability on Carpet
The weight of the chair, as well as your weight, will press down on the mat. When the mat is on a softer surface, it can sink down under the casters of the chair, causing the edges of the mat to rise up if the mat is made of thin, flexible vinyl or plastic. That makes it harder to move along the mat, too. Yet glass and rigid plastic aren't the best either as the weight of you and the chair pressing down on one part of the mat can make the entire thing tilt and lift up at the far end.
For carpet, then, you'll want a thicker but flexible material that can hold weight a little better. You'll also want something that has tiny spikes on the underside to help anchor the mat to the carpet.
If you have a very thin carpet that isn't that soft or springy, then a rigid glass or plastic mat could work. Just make sure the mat either has those spikes to anchor it or has some type of non-slip grip on the underside to prevent the mat from sliding around.
Hard flooring might not need the help of a mat to make it smooth enough for your chair to roll over easily, but that mat will protect the floor from scuff marks and scratches. Hard flooring can use either glass or plastic/vinyl mats, but you won't need the spikes, obviously. If you get a glass mat for use on a hard floor, make sure the underside of the mat has some sort of non-slip grip.
Watch out for the Edges
Sometimes your chair is going to roll off the mat, either by accident or on purpose as you move the chair over to another desk or cabinet. The edge of the mat is going to make all the difference here. Look for mats (no matter the material) that have beveled edges that allow you to roll the chair right back onto the mat when you want to get back to your desk, without having to get up and push the chair in front of you. Even thin mats can be annoying if they don't have beveled edges.
If people in your office already have mats that they seem to like, look at what they're using. If you don't have that model, or if you're looking at glass chairmats online for a home office, look around and be sure you get something that won't lift up and that will protect your floor and your peace of mind.