2 panels for the window opening around 900mm, why we do 2 panels?

most of the provider/agency they suggest clients to do 1 panels for the opening around 900mm, or 2 panels of the opening 1800mm,

we never do that, because for the solution of the best width of louvers is no longer than 750mm,

the product we use is solid vinyl (kind of formed pvc) with aluminium reinforced, its much stronger than the one of solid vinyl only ,even for the timbers one,

we seen lots of the customer who had the existing shutters, the lovers over 900mm almost have bowed,

but we still not do the louvers over 900mm, its not lasting longer, we use more materials(more stiles) on the more panels to let the clients use longer time,

we thinking about the customers,

for the opening of 1800mm, we do 3 panels at least,