It's possible that it was a term used in the past to describe soaps that were specifically formulated to be more moisturizing or emollient. This might have involved adding additional fats or oils to the soap recipe, or it might have referred to a particular type of soap that was known for its moisturizing properties.
Here are some possibilities:
* The term is outdated: The term might simply be an older way of referring to moisturizing soaps.
* It's a specific brand: The term might be associated with a particular brand of soap that is no longer in production.
* It's a regional term: The term might be more common in certain regions or countries.
To find out more, you could try:
* Searching online: Try searching for "fatted skin soap" or "moisturizing soap" to see if you can find any information.
* Contacting a soapmaker: You could contact a soapmaker or a soap-making expert to see if they are familiar with the term.
* Looking for historical references: You could try searching for historical documents or books on soapmaking to see if the term is mentioned.
Without more context, it's difficult to say for sure if "fatted skin soap" is still available or what it might refer to.