Additional items you will need

- double-sided table

• https://www.3mcanada.ca/3M/en_CA/p/d/v101211082/
• I used this and trimmed off any excess

- Magnets

• got some off amazon. size posted was 20x10x5mm
• https://www.amazon.ca/dp/B0BLNJW767 
• size given is about 1mm smaller on each side

I printed with a 50% infill, so thats the highest you should go. You can probably go as little as 10 to 20%, but it shouldnt really that much more or less filament.

I am aware that the magnets with the combined tape is not perfectly flush with the base of the print. this is to account for any imperfections in finish of print, and material. 

if you plan to do a batch at once. try to avoid placing the foam tape between magnets. once you start stacking these, it will eventually deform tape enough that it become less than perfect. I found that out the hard way.

Overall, it works well enough.

Note2 (optional): Print this upside down, then turn with a 45 degree angle. That way the lines (assuming it shows) are all facing a specific direction and no support is needed if you do this. but this is up to you.

No, you are not allowed to sell this for profit