Digital BW, The Print

Other than chip difference, I always wonder if recent Epson 6-color+ 
printer series (R220 R260 R280 R300 R320 R800 R1800 R1900 2100 2200 2400 
2880 ...) are using the same inkjet cartridge bodies.

Also Epson C64/C66/C84/C86/C120 ... using the same inkjet cartridge 
bodies, other than chip difference.

And if Epson R-family cartriege bodies, the same as C-family cartridge 
bodies, other than chip differences.

Thanks,
- Philip