Inspired by the film Avatar (2009)
In the opening scene of the film, set in the mid 22nd century, we see a non-Jewish funeral for the protagonist's brother, in which his body (in a cardboard aron) is put into an incinerator.
While cremation is assur, the scene made me wonder whether a cardboard coffin would be appropriate. As far as I'm aware, there is no halachic issue with being buried in cardboard, as it biodegrades relatively quickly. However, would it be acceptable, from the angle of kavod hamet to bury a body in the above described aron, rather than in a wooden box or just a tallit/tachrichim?