All load signs shall be given related to the global co-ordinate system. Depending upon the glass package which shall be loaded, this will define a suction or a pressure load. The z-axis is showing the positiv direction.
So a positive load onto the inside (glass package 1) is a pressure load.
A positive face load onto the outside (largest glass package) is a suction load.

All units are in N and Millimenter. To give a face load of 1.0 kN/m² you have to write 0.001 N/mm² or using the exponential notation 1.0e-3 N/mm². This will divide your load by 1000.

In this shown example al pressure load is applied onto glass package 2 of -1.0 kN/m² = -1.0e-3 N/mm² = -0.001 N/mm².