New recommended spray painting method for 3d wall panels:

Step 1.  Ensure that the routed 3d wall panels meet the next adjoining panel. Leave a gap of about 1-2mm in between panels for fillers.

Step 2. Use “polyester putty” (commonly used in vehicle spray painting industry) as filler for gaps, points and nail holes.

Step 3. Apply the putty with a spreader, ensure all gaps, joints and holes are joints and holes are fully filled. Allow drying time in between application for putty to be fully settled.

Step 4. Sand off the excess filler covering gaps, joints and nail holes. Do a light and fine sanding over the entire surface of the pre-primed 3d wall panels as preparation to receive paint.

Step 5. Thin layers of paint are to be applied in between drying intervals.

Step 6. Advisable to engage skilled professional spray paint applicator for best result.

Extended reference: New recommended installation idea for 3d wall panels.