A device for binding sheets in a pack, the device having a flat rectangular sheet element in turn having, along one major side, a number of flexible tongues arranged combfashion; and a closing strip extending along the major side. According to some embodiments, the processor determines a trace area of the package from the package measurement attributes. Other examples are also disclosed and claimed. The non-solid matrix then can be solidified to form a solid matrix. The first request does not include the primary authentication token. The build material comprises a carrier material and nanofibers.