This is the goldilocks ornament, not too big, not too small, but just right. It is 9-sided or Nonagonal, so looks really nice.
It is 110 mm from the very top of to the bottom, and about 47mm at the widest point.
I found many ornaments to be too large for the smaller UK Christmas trees, houses smaller, so trees smaller. Of course, you can scale it up by any percentage you like for much larger. I would be careful going smaller, as the top will get very thin.
Remember at 200% scale you are at 220mm hight, so check your printer volume before printing.
If you need hooks for the ornament, then these were designed to work with it. Christmas Ornament Hook
I have used two colour PLA and that looks nice (blue and red, gold and silver), I have also used single colour (dark yellow) and they have all turned out fantastically.
Use your most decorative filament, the fancier the better. I used PLA, but anything nice will work well.
Use vase/spiral mode.
No supports needed
No brim needed
0.5mm layer width
0.2mm layer height
It has a small base, but I have had no trouble with it staying put. Removal should be straightforward.
Print the ornament with the top (where the top is glued on) to the bed and let the ornament spiral upwards – towards what will be the bottom.
Print the top, with the eye for the hook or cotton to the top, with the flat base at the bottom.
A dab of superglue on the top, then carefully hold in place. I use superglue, but the one you like should work with the type of plastic you use.
This is printed in vase/spiral mode, so the walls are comparatively thin. this means that if you push too hard on the sides, it will break. So, treat it gently and it will last for years.
If you get little blobs on your print, it might be due to the Power Out system that saves the state to the SD card periodically. I have it turned off, but it does happen with many short curves, like this has.
I have not tried this yet, but am planning on doing so:
Spray snow to put a light dusting on the top, so it looks like snow fell onto the ornament
A little glue and some glitter to jazz up a single colour – to match your tree
For the children, draw their own designs to make them personal – for this year and the next few.