Your file must be a high-resolution pdf.
Colour coding in cmyk, not in pantone (printing only in offset) not in RGB (they are only screen colours, so in print you will have a different colour result than on the screen).
5mm chamfers on each side and cut points. All elements of your mock-up (lettering, photos, drawings, logos) must be placed at least 5mm through the cut points. If you want a design or photo to stand out, it should be up to 5mm. outside the cut points.
Fold points if your form folds.
All fonts and elements of your mock-up should be outlines or curves.
For offset printing, for more correct colour accuracy, we recommend printing a certified digital colour test, it only applies in the case of exclusive printing and this is because in co-printing there cannot always be colour accuracy, the tolerable margin of error in the shade of the colours of the forms that are not accompanied by a certified essay or relate to co-printing is + or - 10%.
Brochure mock-up files, when 2-sided, should be on 2 pdf pages (either separate or in the same pdf).