According to the
Jewish funeral traditions, the body should return to the earth as quickly and naturally as possible. Therefore, a kosher casket needs to meet some requirements, such as being completely made of biodegradable materials and having a simple design to reflect the equality of all people.
Sources:
Szczesniak, Daniel. The Aron: Jewish Burial Caskets & Where to Find Them. (n.d.). Retrieved from https://www.usurnsonline.com/burial/jewish-burial-caskets-where-to-find-them/
Complete Guide to Jewish/Orthodox Burial, Rituals and Caskets. (n.d.). Retrieved from https://trustedcaskets.com/blogs/funeral-information/complete-guide-to-jewish-orthodox-burial-rituals-and-caskets