Ice sculpting obviously begins a single critical ingredient: water. Not all water works equally well for artistic purposes. Carving experts typically favor pure, clean water that makes for the smoothest, clearest ice.
But the relative clarity or cloudiness of ice aren't the only indicators of purity. When dirt and other particulates hover in water, they may attract air molecules, too, and the ultimate result is ice that looks less than pristine.
The conditions in which the water freezes also play a role in clarity. To make the clearest ice for sculptures, it's important to remove as many dissolved gases as possible. Some companies use large machines to circulate the water, pushing out air bit by bit. But you can accomplish the same thing at home by boiling water a couple of times and then freezing it.
Many artists prefer the glistening, pure appearance of clear ice for their work. But that doesn't mean translucent or opaque ice doesn't have a place in sculpting. Just as with different types of rock, sculptors know that they can incorporate materials with different qualities to add to the pieces they create.
They can add color, too, with dyes, gels or sand. Colored lights (often LEDs) offer the most spectacular effects. After sunset, these bright bulbs bring out subtle details and intricacies that are difficult to see in daylight.
Of course, before you can start carving, you need ice. Manufactured ice comes in an array of sizes for carving. Businesses may opt to purchase specialized machines such as the Clinebell Carving Block Maker, which has two 40-gallon (151-liter) tubs that produce ice crystal-clear blocks every three to four days. The resulting blocks measure 40 x 40 x 10 inches (102 x 102 x 25 centimeters) and they crush the scales at more than 300 pounds (136 kilograms). If you're a hobbyist ice carver you may balk at the investment required for one of these machines — they cost more than $6,000.
Natural ice that's cut from frozen lakes can be even larger than human-made blocks. It's this variety that's most often used for ice buildings and structures that require massive chunks of ice that serve as foundations. These can weigh as much as 2 to 3 tons (1,814 to 2,722 kilograms) and require massive machinery to move and place them.