Is a glass bottle a good thermal insulator

So I bought a small glass bottle of capers. Is the bottle a good thermal insulator? I need it for a project.
Also is plastic a good thermal insulator too? I got a tiny tomato paste can with white plastic in it.

Is it because you want to keep something warm or cold?

I hope you are talking really thermal and not electical.

****Like the answer before me... go try find something that is like a coffee cup, but not those paper ones, the one's that are made of styrofoam. It will work better for both ways, hot or cold.**** FORGET ABOUT THIS I JUST READ YOU CAN'T USE STYROFOAM.

I would go with the plastic. Can you put one inside the other and try to insulate with a layer of something? Like sand or earth perhaps? I would put the glass inside the plastic. In that order if possible.

No. Glass and plastic tend to heat up very quickly and in some cases, plastic may melt if put in extremely hot temperatures. If it does not require boiling something or melting something, I would suggest to use a Styrofoam cup to hold a hot liquid, as it was made for that purpose. Since you can't use Styrofoam, you could use a thermos, which uses a vacuum to insulate the contents. Otherwise, use the glass, it's your best shot.

I'd definitely suggest a thermos. Its your best bet. Forget glass and plastic. They are poor insulators. Alternatively, you can put your hot liquid in a very thick plastic, insulate it by storing in a bag full of cotton materials. Make sure you pad the plastic heavily to avoid loss of heat.
Goodluck.

So, so...

Metal is worse...

Styrofoam is better...