Technical considerations about cross fold leaflet design
When designing a cross fold, it is necessary to define in your design software a 2-page document , the size of the brochure flat open.
Usually all 4 panels have to be the same size. But there may also be the case of asymmetric cross folded leaflets, with two panels being narrower than the other two.
A 3 mm bleed area must be defined and the elements that must bleed off should also extend 3 mm beyond the page edges. It is advisable to respect a safety margin of 3 to 5 mm around the 4 page edges, in which no element should be placed (other than those that extend out of the page). It is essential to respect this rule; otherwise, when trimming the cross fold brochure, elements placed very close to the paper edge may be partially or totally sliced.
As for resolution of pictures and logos. image resolution must be high enough as to guarantee quality reproduction.