Round miniature bases with slot
Slotted round bases hold metal or resin miniatures with a tab underneath, and buying them in odd sizes gets expensive. A useful base is 25, 32 or 40 mm in diameter, 3 mm thick with a 1 mm bevel around the top edge, and a centred slot 20 mm long by 1.5 mm wide that goes fully through. Printing them flat with a 0.12 mm layer height gives a clean surface for texturing, and PLA handles them without warping.
SpeakCAD makes it easy to produce the exact diameter and slot width your models need, including odd combinations like a 28.5 mm base with a 2 mm tab. Adjust the bevel or add a magnet pocket in the chat, preview for free, and download the file only when you are happy.
Make a round miniature base 32 mm in diameter and 3 mm thick with a 1 mm 45-degree bevel on the top edge, a through slot 20 mm long and 1.5 mm wide in the centre, and a 5 x 2 mm magnet recess underneath.