This claim is being verified by Guinness World Records, according to the agency.
To promote their Proglide blades, Gillette wrote a campaign on a man's shaved whiskers. The ads are 100 microns in size. Blown up versions were turned into a print and poster campaign. Also, according to the agency press note: "The actual hairs were then placed in men's bathrooms at airports where they would typically freshen up. With the hairs was a QR code through which people could access extra content showing what was on the hair."
So! That happened. Video below. Ad agency: CLM BBDO France. Previously:
• world's smallest ever brochure.
• world's smallest ever Guinness beer ad.
• world's smallest ever biplane beach banner ad.