Cal. Pen. Code § 2813
The director may provide for the manufacture of small articles of handiwork by the prisoners out of raw materials purchased by the prisoners with their own funds or funds borrowed from the Inmates' Welfare Fund, or from raw materials furnished by the director without compensation therefor as provided in this section which articles may be sold to the public at the state prisons, in public buildings, at fairs, or on property operated by nonprofit associations. State-owned property shall not be given to prisoners for use under this section, unless all proceeds from the sale thereof shall be deposited in the Inmates' Welfare Fund. The director may provide that all or a part of the sale price of all other articles manufactured and sold under this section be deposited to the account of the prisoner manufacturing the article.
Ca. Pen. Code § 2813