This model is resliced to add better stabilization to the Ikea lack and can be used in addition to traditional lack corner brackets. When I first printed the original model I noticed it had a rigidity issue, the part itself flexed due to how thin it was (4mm), this light remix doubles the thickness to 8mm on z-axis without changing X or Y scale.

Materials Needed to Mount:

For mounting all you need is (5) #10 or #10 Philips or Torx screws (wood or deck screws) per corner, ~1" (25.4mm) length is ideal and drill bits to drill the pilot holes for the screws. Be sure not to over tighten or else the PETG will crack. 

Note: The best screws for Ikea lack usage will heave threads close to the drive/head portion of the screw.

Mounting Orientation:

When mounting the corners, I advise to fully assemble the Ikea lack table and then add these after all other corner and extension brackets have been added.

Print Profile Notes:

Nozzle: Suggest 0.6mm nozzle for fastest print time, 0.4mm will work just fine though.
Wall Loops: 4 wall loops on 0.4mm nozzle, 3 wall loops on 0.6mm. 
Layer Height: Suggest 0.24mm (for 0.4mm nozzle) or 0.24 for a 0.6mm nozzle to maximize strength
Infill: 30%-50% gyroid (50% default for maximum rigidity)
Brim: Printable with no brim.
Material: PETG or ABS/ASA (scale uniform by 100.7% for asa/abs). Default profile is PETG Generic
Color: Any, Example was printed in Bambu Lab PETG-CF
Print Orientation: larger surface in contact with printbed
Supports: No Supports required, prints flat.
3d Printers: Should be printable on any printer.
Filament amount required: 41.23g per corner reinforcement bracket