It is Stackable! There is also a non-stackable, flat-bottomed version. There are 2 versions of each. One says "milk crate" the other is plain. Put your own name on it. I used Techniqu font in Tinkercad.

The stackable crate (S) needs support for the bottom edges. I had to use a support blocker above 2.0mm, otherwise mine would print it in NON-VASE MODE even after passing 2.5mm layer height. The flat-bottomed crate (F) does not need support.

Inspired by "Milk Crate https://www.thingiverse.com/thing:3349271". It's not a remix. I rebuilt it from scratch to print in vasemode. I printed the original file (MILK_CRATE_13.stl) at 75mm square. I looked at it to build this one.

Vase Mode
.25mm layers .8mm wall thickness & linewidth (I use a .4mm nozzle)

Flat-Bottomed Crate (F) bottom thickness = 4 layers = 1.0mm. no support

Stackable crate (S) bottom thickness = 10 layers = 2.5mm. with support only for bottom 2.0mm and a support blocker above 2.0mm

the STACKABLE CRATE 3D object is solid except for a void from 1.0mm up to 2.5mm so that the bottom of the crate is only 1.0mm thick in the center with thicker edges to accommodate the 2.5mm stackable bottom, otherwise it takes much longer to print a solid 2.5mm thick bottom.

made with Tinkercad