This is a new category for Merlin Antiques and one about which we don't know a lot except that they are ceramic! I've been told that most food and cosmetic items were packaged this way until 1910 when cheaper packaging was developed. The pot lids are transfer printed usually in black and sometimes in other colors or more than one color. The lids and pots were usually thrown away in privies and dumps after the contents were gone similar to tossing the used toothpaste tube in the waste basket. Thus, pot lids are the ephemera of the last century. Although it is nice to have a pot to go with a lid, they usually were separated when thrown away. The important item is the lid, its print and its advertising.