Critters from the first mason drop can be upgraded to increase coin values to 5. If the card was massed, the new coin value is 5 * the number of cards that were massed into it.
Upgrade an “old” label card (any label card less than 10 coins). This does not cost a coin, but you need to have one. The coin is returned to you later.
Upgrade an “old” artist card (any artist card less than 10 coins). This does not cost a coin, but you need to have one. The coin is returned to you later.