This statement is usually true, and most books on collecting pottery site this as a "Golden Rule", but unfortunately, it simply isn't 100% failsafe. Our reproduction Shawnee Smiley Pig, for example, is 100% full size. Standing side by side with an original, you would not be able to tell by size alone that it is a replica. The process of overcoming the "size factor" is difficult and may not be within the technical skills range of all fake artists, but it IS possible to do. Never use this one test as definitive or you may get burned. If the jar is 5-7% smaller than the original is stated to be in the collector books, then chances are it is fake. But just because it is full size is no guarantee of authenticity.

No. This is simply not true. Even the most obvious fakes are usually structurally of relatively high quality. Ceramic slip has developed over the years into a quality, predictable product, and even the "cheap" paints and glazes are usually of better quality than those used 40 years ago. Some imports from China may be lightweight, but domestic fakes are more likely to be "boat anchors" due to poor pouring habits. There is no way to tell by weight how old a piece is. 

Never get comfortable with the idea that any certain piece has never been faked. The scam artists know their audience and are always looking for new pieces to surprise you with. It's best to be cautious, even if you "heard" that a piece is safe.

Two words. Shill bidding. Watch private auctions especially closely (We recommend you simply don't bid on ANY vintage pottery auction that is "private". A lot of bids on a questionable piece is another warning sign, not a reassurance.

This is simply the biggest myth of all. Even for those who don't care about the collectible value of a piece, a fake still hurts everyone. Fakes cut to the heart of trust, and eBay is built on trust. Any person who bids in good faith on an item, and pays their hard earned money, deserves to get what they paid for. Fakes may make the scam artists richer, but the rest of us are made poorer, in many different ways.