What are the different types of stamps available, and what purposes do they serve (e.g., commemorative, definitive, airmail, etc.)?
How did the use of stamps revolutionize the postal system in the 19th century?
What are the most valuable stamps in history, and what factors contribute to their high value?
What role do commemorative stamps play in reflecting cultural or historical events, and how are they typically used by postal services worldwide?
How do modern technologies, such as digital printing and QR codes, impact the future of postage stamp usage and collecting?
What are some of the most famous or rare stamps in the world, and what makes them unique or valuable?
How has the design and production of postage stamps evolved since their introduction in the 19th century?
What are the key factors that determine the value of a postage stamp to collectors and philatelists?
What are some common errors or misprints in stamp production, and why are they particularly sought after by collectors?
How can collectors determine the value of a stamp, and what factors contribute to a stamp's rarity and worth?
