Complex sentence: The cartoonist began submitting story ideas for the multi-page comic strip to Hefner for approval and was allowed (with "Playboy" substantial budget) to travel for research, photography, and sketching.
Split into simpler sentences: The cartoonist began submitting story ideas for the multi-page comic strip to Hefner for approval. He was allowed (with "Playboy" substantial budget) to travel for research, photography, and sketching.