He began creating comics as a child. Later he worked for the Dutch comics pioneer Marten Toonder. Kruis started his own comics career drawing Prins Freddie for the magazine De Havenloods,^[2] but became famous thanks to his series of one-pagers called Jan, Jans en de Kinderen ("Jack, Jacky and the Juniors"). It first appeared in the woman's magazine Libelle on December 12, 1970. In German-speaking Switzerland it appeared in the magazine Spick which targeted children and teenagers; and in Germany Favorit published it for some time under the name "Ulli, Ulla und die Kinder". He also had a gag comic named Gregor running in Tintin, between 1965 and 1966, which was later reprinted in Pep.^[3] Kruis took over Sjors en Sjimmie from Frans Piët in 1969 and modernized the characters, including a less stereotypical depiction of Sjimmie's black features. The series was later taken over by Jan Steeman.^[4]

He was furthermore active as an illustrator of novels, magazines, advertisements and record covers.^[5]

Kruis received the Order of the Netherlands Lion in 1996.^[6] Two years later he retired.^[7] Daughter Andrea Kruis has followed in her father's footsteps.

In 2013 his career was celebrated in a one-off glossy-zine; this includes previously unpublished gags of a comic about an infant punk raised by a gay couple; hence the nickname "Jan, Jan en de Kinderen" ("Jack, Jack and the Juniors").

Jan Kruis died in his hometown Mantinge (Drenthe) at the age of 83.^[8] On 20 January 2017, a good friend of the family informed the press about his death on the previous day.

• Jack, Jacky and the Juniors

• Official website
• https://www.lambiek.net/artists/k/kruis.htm
• http://www.libelle.nl/lifestyle/interview-jan-kruis