Cinderellas are labels that look like stamps but are not real stamps. Sometimes business might make them for advertising. Some have been produced from the winning designs of 'design a stamp' competitions.
In 2013, StampIT partnered with Edinburgh Zoo to run a 'design a stamp' competition to celebrate the zoo's 100th anniversary. The winning stamps were made into two cinderella miniature sheets.
In 2004, StampIT partnered with Girlguiding East Lothian. The winning stamps made this cinderella miniature sheet:
This one was from a Scottish competition to design a stamp for the millennium:
This is a label which was produced to celebrate the 30th anniversary of the moon landing:
These are Christmas labels which are produced in many different designs to raise money for charity:
This one looks very like a real stamp but it is a cinderella. It is a non-official railway stamp: