Whether it's sorting out a bead soup or salvaging a spill or accidental mixing, separating out mixed beads by size feels like an unfortunate necessity of beadwork. That's why one of the first things I made when I started 3D printing was a sifter tower to help speed that process up.
How it works: Stack the tower with which sizes you want to sort out, largest size higher up. Place the bottom cup onto the bottom, then pour your bead mix into the top cup. Put the lid on, and then holding the entire thing in your hand, give it a few shakes up and down and/or in a swishing motion. The beads that are the size labeled on the cup or smaller will sift through the layers until they come to rest on the layer that's too small for them to pass through, with the smallest ones gathering in the bottom cup. If some beads get stuck in a cup layer, simply invert the cup and gently poke them back out with a pencil or any other handy tool.
Each cup is labeled with the bead size and bead measurement for the bead that will pass through it into the holder below. The cups that fit together tightly and need a light bit of squeezing to separate them to help guard against accidental separation while being shaken.
Cup sizes are as follows: 6/0 Miyuki (4.5mm), 6/0 Toho (4mm), 8/0 (3.2mm), 11/0 (2.1mm), 15/0 (1.5mm)
Please note that the colors may be slightly different than in the photos due to differences with in filament spools, but always will be in the same color family.
Sifter cups are 1.5 inch in diameter, with each cup being a bit under an inch tall. When all assembled, the entire stack of 5 cups plus base and lid is a little over 4 inches
All the parts are 3D printed using PLA, (a bioplastic,) and can be customized.
Lindsay Star also did a super awesome write up on the full sized original version of these on her blog here: http://artelements.net/i-needed-this-tool-24-years-ago/
Thanks for looking!