This classic Belgian definitive set features the engraved left-profile portrait of King Baudouin, a long-running series widely used for everyday postal needs during the mid-20th century. The stamps shown include denominations of 10F, 15F, 18F, and 2.25F, each printed in distinct colors typical of Belgian postal design traditions. Produced using fine line engraving, these issues are appreciated by collectors for their sharp portrait detail, multiple printings, and numerous postal-usage varieties. Complete multi-value groupings such as this provide an excellent foundation for building specialized Baudouin definitive collections.