This Montini brick is 1 wide, 9 long, and 10 bricks high. I customized the brick to be a frame for this lithophane of a picture I took in the NY Metropolitan Museum of Art. I believe the stained glass window is by Tiffany.
I haven't seen anyone embed a lithophane into a construction brick, so hopefully this is a new idea.
Montini building bricks were produced from 1961 to 1969 in the Netherlands. They were originally made from soft, pliable polypropylene. The diagonal fins bend slightly around the pips of the other block.
Please do not mix these with original Montini parts. PLA is much harder than the original bricks, and the layer ridges act like sand paper. You will wear out the original Montini bricks very quickly.
Just like the vintage original Montini parts, these are compatible with classic Lego full height bricks.
Original stained glass window information:
Maker: Tiffany Studios
Original picture credit: Myself