This is a very interesting topic to me. I have collected fancy 20th century Venetian beads for many years and only started with the trade beads about 3 years ago. Because I gravitate to complexity in a bead, I tend to prefer millefioris to other types of trade beads. Still, I decided to buy a strand of six layer chevrons to have as a type piece. Even with the Picards' book on chevrons, I did not feel able to distinguish between reproductions (especially if artificially aged) and genuine old chevrons. I bought two strands of big six layers from reputable sellers on ebay (sellers that I have also seen on this site) and that's it. The fakes are definitely an issue and have stopped me in my tracks as far as buying any more or stretching for seven layers. Also, I can't really wear the large chevrons on a day to day basis, unlike the trade beads and fancy Venetians, so I like the big chevrons as objects rather than wearable pieces.