Setup inventory for multi diamension

Hi Xtuple consultant,

can any one advice how do i setup same stock with multiple diamension for xtyple erp ?

for example we buy GI Coils 0.4mm in thinkness, but it come in different Width and different Length for the same thinkness, should i create under 1 stock item or multiple stock item ?

sample :
the following stock G.I - 0.4MM, come in 4 different width and length, should i setup as 1 stock item or 4 stock item ?

G.I - 0.4MM (THK) X 1219MM(W) X COIL
G.I - 0.4MM (THK) X 4'(W) X 8'(L)
G.I - 0.4MM (THK) X 4'(W) X 10'(L)
G.I - 0.4MM (THK) X 137MM(W) X COIL

Pls adv.

Viv