Pint glass small pits which aid in nucleation, allowing the gas within it to be released more easily, thus preserving the head. Without the aid of these pits a regular pint glass will keep a head for only 3 or 4 minutes before appearing 'flat'. The markings come in a variety of styles ranging from a simple circular or square hatched pattern to more complicated branding messages. Pint glass collecting is an increasingly popular way for individuals to commemorate their visits to popular tourist destinations, most notably to microbreweries or sports arenas. These destinations often sell pint glasses adorned with their logos,
Pint ml (20 fluid ounces). With the allowed margin of error of 0.5 fluid ounces, a "pint" that is less than 554 ml of beer is an offence, though—to the detriment of consumers—this regulation is often violated and rarely enforced. After metrication in Canada, companies sold milk and other liquids in metric units so conversion issues could no longer arise. Legally speaking, although some British imperial units are still legally usable in Canada, as a result of Canada's colonial history, the "pint" served in drinking establishments in Canada should be the larger 20 ounce British imperial pint, rather than the smaller