When buying an unframed artwork, should I buy a frame myself before I receive the artwork?

Never buy a frame before you receive the artwork!

Even though dimensions can be provided in advance, and are usually displayed on the artwork detail page, there can still be errors or misunderstandings: 

• seller sometimes does not provide 100% accurate measurements: a difference of a few mm can require a different frame size
• when the artwork is shipped in a tube, it can then be mounted on different wood stretchers, resulting in various final sizes
• the canvas can be folded on the sides of the mount and it will add more thickness, although the main area of the painting still have the same size
• it is not uncommon to have small imprecisions when the dimensions are not given in your own length units (cm/inches/feet)

For this reasons, please always wait for the artwork to arrive, then take very accurate measurements, or bring the art directly to your local frame shop: it is always the bet solution to make sure you will have a perfectly mounted artwork matching your interior!