"A smoking jacket is an item of clothing, now relatively rare, specifically designed for the purposes of smoking tobacco, usually in the form of pipes and cigars. Styles vary; the classic smoking jacket is a waist-length jacket made of velvet and/or silk, with a shawl collar and turn-up cuffs and toggle or button fastenings. Usually, they are made in rich colors such as burgundy and bottle green.
The smoking jacket became a popular accessory in Victorian times, when it was believed that the sensitive and delicate nostrils of ladies would be assailed by the pungent fumes of tobacco clinging to everyday clothing. Consequently it became de rigueur for every considerate gentleman to don his smoking jacket before lighting his cigar or pipe, usually after dinner. Smoking caps were also sometimes worn for the same reason. In addition to protecting the wearer from the aroma of tobacco, the removal of the smoker's suit coat and the covering of the shirt, tie and vest with the smoking jacket would protect all these garments from ash and embers.
The modern rarity of serious and dedicated pipe and cigar smoking as well as the vagaries of fashion mean that in today's world the smoking jacket is a rare item; the high cost of quality items also prevents its widespread use. However some cannabis smokers have adopted a smoking jacket because pipe smoking is more widespread in the cannabis smoking community. Other than visiting vintage clothing stores, a quality smoking jacket (which can, and frequently does, last a lifetime) would now have to be specially tailored or found on online high-end stores."
I would take umbrage with that statement. It is clear there are many serious pipe and cigar smokers in today's world and judging by Anthony's classic choice the smoking jacket is not at all a rare item.