In resin art, the terms "2:1 ratio" and "3:1 ratio" refer to the proportions in which the resin and hardener should be mixed. These ratios indicate the volume or weight of resin to be mixed with the corresponding volume or weight of hardener.
For example, a 2:1 ratio means that for every two parts of resin, you would add one part of hardener. Similarly, a 3:1 ratio means that for every three parts of resin, you would add one part of hardener.
It's important to follow the manufacturer's instructions and use the specified ratio for the specific resin product you are using. Using the correct ratio ensures that the resin cures properly and achieves the desired hardness and durability. Deviating from the recommended ratios can result in incomplete curing, tacky or soft resin, or other issues with the final artwork.