Hi, I would like to ask for custom made cabinets, is it the norm for the back of the cabinets to be fitted with a thin pc of plywood and laminate only. My carpenter says this is the normal but I find it not solid enough. Wondering if the carpenter is short changing me.

My whole carcass is in thick wood and not those thin wood like ikea backing...

It'll not be as thick as those outer surface but will definitely not those IKEA plywood. Normally we won't be particular about it as it is leaning against the wall and you won't feel the thinness, but if you think it is not solid you may want to give a little shake to your cabinets to test out the durability.

By default, carpenter normally will just use a 1/8 inch panel for the back/rear of the cabinet. Of coz one can request for 3/8 inch. The inner depth may turn up slightly smaller.