US Coins
World Coins
Paper Money
Collecting 101
Coin Market
Community
Events
Coin of the Year
Archive
Marketplace
Pricing
Print
US Coins
World Coins
Paper Money
Collecting 101
Coin Market
Community
Events
Coin of the Year
Archive
Marketplace
Pricing
Print
friction
Collecting 101
Learning to recognize friction
By F. Michael Fazzari
Apr 26, 2019