Gate marks

[Anthony Averella]

If a piece of CI has no noticeable markings on the bottom, is it possible to date it just from the gate mark on it if it has one?

[Roger Barfield]

Not really, some bottom gated pieces were made up into the 1930's and 40's.  You have to look at the entire piece and the design and markings.  Even then you are often times guessing as to when it was made.