"Fiep Westendorp's illustrations started appearing in magazines and in advertising, and at the end of the 50s, her books started hitting the shelves.
She became famous for her cat characters, Pim and Pom, and also for these, who are called Jip en Janneke."

Apparently there are still many items with these two: domino, onesies, stickers, stamps......Oh my.... we just wnat them all!!! (via skinny la minx)