The unique ProCreate formula allows for easy customization of work life and hardness/flexibility by varying temperature and the mix ratio of base to hardener. The standard mix ratio of 1:1 at 75°F (24°C) allows for a work life of around 120 minutes. A temperature decrease of about 20°F (11°C) will double the work life. Likewise an increase of the same temperature will result in half the work original life. Note that curing above 95°F (32°C) is not recommended since it can soften the mixed putty and result in the loss of sculpture shape and detail. A more flexible cure may be achieved for organic shapes by using more of the black colored hardener. A harder cure may be achieved for hard edges, machines and for easier standing and filling by using more of the white Base putty (see ratio chart for more details).