To allow people with colour blindness or colour confusion to differentiate between the three levels of card (green triangles, yellow squares, and red circles or ovals).
The popularity of hockey card collecting has gone down over the years, but there are still conventions and shows. I'm a hockey card collector myself and I highly recommend it to all hockey fans.
in my opinion the most valuable hockey card would be rocket Richard 's rookie card
green
a card that has a players/ goalies stats and his picture
red
Silver
lugia
Depends on which signdd Kevin Lowe hockey card we are talking about here. Ask www.beckett.com
A thin point sharpie is the best pen to use when autographing a hockey card.
Here's a free hockey card price guide, http://www.tophockeycards.com
The price of the card depends on what player is on the card, how old the card is, and how famous the player is.