Experience Nature 2024 / 2025: division illustration on back!

There is something special going on with the two-part, perforated paper with a monochrome image on the back of the self-adhesive Beleef de Natuur stamps from 2024 and 2025. There is a striking difference between the two years! The wavy line separating both parts of the printed overlay on the reverse side of each stamp features opposing wavy lines: * Stamps with the peak of the wavy line in the center are sold at local postal points. * Stamps with the trough in the center of the wavy line are distributed via subscription or order. * The cause and reason for these peculiarities and distribution points are (yet) unknown. * Whether the difference between the two stamp sheets is collectible is a personal decision for each collector.