I specialize in pressed pennies that are rolled on uncirculated pre-1982 copper cents.  Exceptions are noted in the descriptions.

Imperfections: Uncirculated coins may still show some imperfections, but major staining or blotches are weeded out, as are off-center coins.  Some sellers try to sell these imperfect coins as “errors” at a premium price, but I sell them quickly at a discount on Ebay or Facebook to get rid of them. Note: when older copper cents are rolled, the difference between the surface copper’s exposure to air and the inside copper may make it appear that there is streaking around some details as is found on zinc coins.  This is a natural occurrence and does not mean the coin is a copper-coated zinc penny.  Easy test: using an electronic scale (inexpensive), copper cents will weigh 48 grains and zinc weighs 38.

Circulated coins: Some machines supply their own circulated coins (notably machines in Canada). When I use circulated coins, the description will expressly state so.

Cleaned coins:  It is getting hard to find BU cents at affordable prices.  We are starting to use some professionally-cleaned copper cents. The description will state whether cleaned pennies are being used.

Zinc pennies: A recent trend has machine supplying their own “shiny zinc pennies.”  Zinc pennies are second-best, but sometimes they are all we can get.  Any zinc pennies will be noted in the description.

Quarters: quarters are pressed on U.S. BU or AU state and national park quarters.

Dimes: dimes are rolled on BU or AU U.S. dimes.

Nickels: All nickels are pressed on uncirculated U.S. nickels.

Foreign coins: I also specialize in pressing foreign coins, especially if there is a foreign theme (such as Epcot Germany designs pressed on German coins). The description will note whether the coins are uncirculated, circulated, have a painted side, or roll short (as often happens).