The design is not intricate like the #Rietveld #Steltman design that I used as the basis for https://hack42.nl/wiki/Gebruiker:Raboof/SteltmanTafeltje , but I'm going to use the same 4cm-thick planks and tried to have that 4cm distance and 2:3 ratios in many places.

It'd come out a bit clearer/nicer if I make the middle vertical plank interrupt the horizontal ones, but that'd reduce the strength.

Yes, I tried with the Golden ratio as well, but I couldn't get that to match the desired capacity nicely :).