[Cob] hybrid, bags or straw..

[Jilly]

Can anyone tell me the differences (benefits / drawbacks) between cob and earth bags? I think it is called earth bags. You put "stabilized earth" into bags and then use cob or plaster to cover over that. 

In the cob books I have, there is a suggestion to use straw bale or other type of hybrid system, particularly for the north wall but also for the speed / ease of building. IF using a hybrid system, what would you suggest - straw or bags? or...?

Thanks for the gypsum info... I need to read more. I am still confused. 

jilly