We want to give you the right support in classifying the glass you bought or  that  is offered to you. For this you need to identify the piece. Beside experience, you have to know who did it,   when, how is was  made and if   reference pieces are known.

For this, the collector needs to know the signatures on the objects and needs to have a list with signatures to compare it.
You need the knowledge of the   techniques used and how these are done
Reference books are very helpful and now  generally available