MARIJUANA advocates are teaming up with Madison Avenue to try to make pot palatable to mainstream Americans — and to the advertisers that want to reach them.

High Times, the 42-year-old must-have magazine for the cannabis enthusiast, has collaborated with Sparks & Honey, an Omnicom advertising agency, on a report meant to prompt big-picture thinking in the marijuana industry. The paper, “Rebranding Marijuana,” was released April 20, the unofficial pot holiday.

“Through the slow legal and regulatory processes,” the report noted, “marijuana is opening up opportunities across a variety of industries, most of which have nothing to do with yesterday’s stoner weed.”

The partnership is an unusual step for a mainstream ad agency, which would usually focus on individual brands rather than an entire — and not uniformly legal — industry.