Alginate is the mould-making material of choice for life casting from the human body — hands, feet, faces, and other body parts — and Chromatic Alginate is the version that makes the process as foolproof as it can possibly be. The colour-changing formula acts as a built-in guide through every stage of the process, removing the guesswork that trips up first-time users and making the results considerably more predictable for everyone.
The colour sequence tells you exactly what the alginate is doing at every moment. Mixed with cold water, the powder turns violet — the mixing stage. As it becomes ready to use, it shifts to pink — the signal to stop mixing and pour or apply immediately. As it begins to set and is no longer spreadable, it turns white — confirming that the mould is taking shape and the subject should hold still. The mould is firm enough to demould approximately three minutes after it changes to white. The entire working time from mixing to set is around four to five minutes depending on room temperature — warmer conditions accelerate setting, cooler conditions slow it down.
The material is dental-grade alginate — the same type used by dentists for taking impressions — which means it is skin-safe, non-toxic, and captures extraordinary surface detail. The powder to water ratio can be adjusted to give a firmer or more flexible mould: 35:100 powder to water by weight for immersion moulding, 50:100 for a spread-on application. The resulting mould is flexible enough to release from body parts with undercuts without tearing, and captures detail to a precision of around 20 microns — fine enough to show fingerprint texture and skin pores clearly in the finished cast.
Alginate moulds are not permanent — they begin to degrade within a day or two and must be cast into immediately. Plaster of Paris, casting plaster, or resin can all be poured into the fresh mould to produce a permanent cast. Includes full instructions. Use within three months of purchase.
Weight: 450g
Setting time: Approximately 3–5 minutes from mixing, depending on room temperature
Detail: Dental grade — captures to approximately 20 microns
Made by: Peak Dale Products, Buxton, Derbyshire
How does the colour-changing process work?
The alginate changes colour at each stage — violet when mixing, pink when ready to use and apply, white when setting and no longer spreadable. This removes the guesswork from the process and makes it accessible for complete beginners as well as experienced makers.
What can alginate be used for?
Life casting from hands, feet, faces, and other body parts — as well as mould making from objects, sculptures, and natural forms. The skin-safe, flexible formula is specifically suited to body casting where the mould needs to release cleanly from complex shapes without damaging the subject or the mould.
How long does an alginate mould last?
Alginate moulds begin to degrade within a day or two of making and must be cast into immediately. They are not suitable for long-term reuse. For a permanent mould, silicone rubber is more appropriate.
What can be cast into an alginate mould?
Plaster of Paris, casting plaster, and resin can all be poured into a fresh alginate mould to produce a permanent cast. The casting material must be poured while the mould is still fresh — typically within an hour of demoulding.
Is it safe for use on skin?
Yes — Chromatic Alginate is dental-grade and skin-safe, non-toxic, and suitable for direct contact with skin during life casting. Always test on a small area first and avoid use on broken or irritated skin.
