American way
 
Secret Jardin Dark Room is a growbox series for indoor cultivation. It is lined with a material with high coefficient of refraction with a special silver mylar (95% reflective) which increases the intensity and distribution of light.
 
It is totally light-proof, with solid structure (stainless steel wire can withstand up to 30kg in weight). It is also quick and easy to assemble even for the larger versions. Can be mounted by only one person in minutes. Instructions detailed photographs.