I think another good signal is how the pipes are displayed on the table. One table that sold estate pipes had a lot of pipes on the table, some in boxes, some sitting on sleeves, some bunched up in a larger box, no perceived order with Stanwells here and there and Comoys scattered about. I don't think one has to ask more than, "Can I look at your pipes?" Other tables have everything perfectly displayed with cards giving the information about the pipes and their prices. Cards, not tags. The table might have only 20 or 30 pipes, but everything is very neat and well laid out. At this table I will say hello and see if a conversation is easy to strike up. I'll offer an overall compliment on how nice the table looks and what beautiful examples he has. I'll offer my card and ask for his card (assuming he isn't dealing with a bunch of customers waiting for me to step aside). Now I've established my identify, I've made it clear I appreciate what he has, and then I will ask if I can look at a particular pipe. Usually the dealer will pick it up and hand it to me. I'll ask what he can tell me about this pipe and you usually get a very informed presentation. Things like checking to see if the pipe cleaner will go through with little trouble, I will ask if he can show me or if I can test it myself. That's what I do and it seems to work out fine. Haven't been thrown out of a show yet.