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 glass look-alike could naturally be affixed to the glass, as long as it is done in such a way that it is not confused with the CE marking". Selling beer in unmeasured glasses without using some other form of calibrated measure is illegal. Half-pint, one-third pint and two-thirds pint (schooners) glasses are also available, and are subject to the same laws. Although the glass must be accurately-calibrated, industry guidelines only require a pint to be at least 95% liquid, allowing 5% of the pint to consist of the foamy 'head'. The Campaign for Real Ale (CAMRA) has described this practice as