This creative extension, which was 3D-printed for amateurs and 3D printer lovers, will upgrade your IKEA Lack table. This extension allows you to stack tables to make a dual-tiered workstation which maximizes the most of your available space. 

The extension raises your table by 110mm (4.33 inches).

The extension is designed with two holes each, so you can attach the extension to the lower table with two screws. I used super glue to attach the upper table (to the extension). No support needed.