Thank you for your interest in Deborah Lippmann. Our nail polish is "breathable". We use the term water permeable. The film of nail polish allows the transfer of vapor between the nail and the environment. Deborah Lippmann Customer Support

Do you need to use the Gel Lab base and top coat with this or can it be used by itself?

You can totally use it without the base and top coat. It’s an awesome product and worth the price!

How many ounces does the bottle contain? Description says that it’s 13.89 lbs!

While have smaller size bottles that come in seasonal color sets of six to a package, this is a regular full size bottle.

Does it smell the same as regular nail polish?

This product does not smell as strong as a regular nail polish probably because it contains fewer noxious chemicals. The guys in my family who always complained loudly about the odor of polish no longer protest since I switched to Lippmann products. Really.