quick, tell me the difference between inverted thumbprint and plain thumbprint ?

beautiful glowing green hemi stand lamp. great condition. standard 9 1/2 size that most of these come in. can come in clear, amber and blue. i actually still need the clear one. no chips or cracks and almost no base nibbles. will include burner and globe and pay shipping again on this one. $500. get better price here instead of what they have been going for in catalogs. can deliver to springfield.

any questions, please ask.