We must make some settings for this process... 

First step;

Click Admin - Custom Definitions - Custom Settings. Invoice settins > General Invoice  must be checked "Import Stock data when printing invoice".

After that step, when we are creating a new invoice we must add a new fields This fields are;

add a data field;

click ... button and 

Choose Table.Invoice Report - Info of invoice stock 

after this step, click ... button from field option.

Choose Explanation 1   all settings are done for this process.. 

Save and close this page, print or preview your design at Invoice