A book or magazine can be provided with  drilling hole . Depending on customer and layout of the portal, this can vary between 1 and 5  drilling hole .

 

It is of great importance that in addition to the number of  drilling hole , the drill mold is also specified. By means of a drilling holes narrow you can specify specifically where the boreholes should go, width of the boreholes and the distances between them. 

How to read a drilling mold