The curing process involves a number of stages that will result in your resin item being completely hard. An incorrect mixing ratio or the addition of too much color can affect the curing time. The resin will begin to cure the moment its two individual components have been mixed together. After this, the resin will go from a liquid consistency to that of a soft gel within 15-20 minutes, after which this gel will firm up further within the next half an hour. The surface of the resin should be hard to the touch within approximately 24 hours, although it can take between 72 hours to a week for it to cure completely.