Platinum Coins: How do I get them

I am new to the game, only been playing about two weeks, and I have just started my own guild. Went to make my cape and I did not have the right resources, didn't even know what the resources were till I checked the forums, but what I can't seem to find is where I get the platinum coins? I am not interested in buying any with real money, but I am wondering if there is something special I have to do to find them. Thanks for the help.

1000g = 1p

Thanks for the help. Another question if I may, will the gold change to platinum at the level or do I need to see some one in game? Thanks again.

it automatically does it

I don't really see the use of 'platinum' but I guess it can be handy when trying to go through big numbers.

You will automatically have 1 platinum when you have 1000g, and 2 platinum when you have 2000g etc.

Yes you will.

Great thanks everyone. See you in game sometime.