Nothing to do with the design - mostly. Either the printer uses specific "transparent" colors or the halftoning process produces a pattern that gives the illusion. In the latter case you would use colors leaning on the light/ white-ish side in your designs or use colors withe redusced opacity over white to enforce suitable halftoning. If genuinely transparent colors are used, you will probably design a document with spot colors. In any case, as with all things for print it is critical that you inquire with the facility doing the actual print for exact requirements and specs before even beginning.
Mylenium