Alginate is the preferred material for making body molds. Not only does it set quickly and capture fine details well, but it generally does not require a release agent unless the body part has masses of hair!

It is easy to work with alginates for making body molds. Simply mix the powder with soft water in the specified proportion and it is good to go. The alginate can be applied on the body part or alternatively, it can be dipped in a bucket of alginate for making the mold.

The best part here is that alginate does not stick to non-porous surfaces. Therefore, making body molds does not usually call for a release agent. However, care has to be taken when the skin happens to be rough, dry or cracked. This necessitates applying a thin coat of petroleum jelly or hair conditioner to fill the texture areas and keep the alginate from holding on to the skin.

Another issue arises with facial hair. Body hair does not interfere with alginate; but eyebrows, moustaches and beards tend to get entangled in the material. Extracting each and every hair from the alginate can be a long and painful task. Instead, filling in the mass of hair with cream or petroleum jelly will make it easier to capture the same in a body mold.

Some artists use the same technique for the hair on the head as well. While this will make the mold making easier, keep in mind that the hair will end up having a ‘wet’ look in the final life casting! A better option is to cover the hair with a bald cap before applying the alginate.

While the hands, feet, torso and other body parts can easily be cast without applying a release agent, demolding will take some time as the fit of the mold on the skin will be quite precise. This calls for some gentle wriggling and moving for the mold to come off from the body. Air should be allowed to enter the space between the skin and mold so that the demolding can take place easily.

When it comes to casting in an alginate mold, plaster is the material of choice. Silicone, urethanes, wax, chocolate and other water-based materials can also be cast in these molds. However, the silica in regular alginate can interfere with the setting of platinum cure silicones.

Then again, the casting has to be done fairly quickly as alginate tends to lose water and shrink as it dries. Therefore, there is a short window for making the life cast. They cannot be reused either. Anyway, the mold has to be peeled off or broken into chunks for demolding the life cast which renders it unusable.

EnvironMolds offers a range of alginate formulations with slow, regular and fast set variations. The LifeMold Silica Free Alginate can be used for casting platinum cure silicones. Fiber-infused alginate is also available with improved strength and delayed shrinkage.