My spouse found the following image on Pinterest and wanted one: https://i.pinimg.com/originals/81/50/4e/81504e8454e1d60c73e0daf83650b0e4.jpg

I made a 2D version for my CNC router and a 3D version mostly for visualizing the 2D version as I changed the parametric values but I did print out a very small version of it for my daughter's fairy and dolls. Unfortunately, the size of the shelf my spouse wanted meant that I needed to cut it in 2 pieces (the whole shelf would have been too big for my router's bed). On the plus side, that meant that I got to experiment with CNC joints and settled on a bulb joint after seeing an example of it (https://www.thingiverse.com/thing:714413/). Everything was cut from a 3/4" glue laminated wood panel obtained from Lowe's (similar to https://www.lowes.com/pd/Greenwood-Forest-Products-Common-3-4-in-x-12-in-x-4-ft-Actual-0-709-in-x-11-25-in-x-3-98-ft-Edge-Glued-Panel-Spruce-Pine-Fir-Board/1000340145). 12" x 52" total. Some of the panels I used had previously been painted white but I ended up sanding everything down and applying 3 layers of Polyshades in espresso.

Note that the online Customizer is incompatible with 2d files so only use it if you want to customize the 3d .stl generated. For 2d, you'll have to download the .scad, modify what you want, and export in your chosen format. I've included the .svg files I generated (I used the split version).