I dyed my coloured-plastic MF8 Kilominx black and applied stickers. It didn't go perfectly, but I'm very happy with the results.

I used 32g (1 box) of powdered Rit Dye Black #15 in 525 mL of water and 225 mL of acetone. This was a 30% acetone solution that, in retrospect, was probably too strong. I kept the solution in the range 40° to 50° C with a water bath surrounding the dye solution container. As this was a multi-coloured plastic puzzle, I was focused on seeing how long it would take to get a consistent colour. I kept the parts in the dye solution for 2 hours and 20 minutes. They stopped darkening after about 2 hours. In the end, I was not successful as about half of the parts are a dark-reddish-brown. The other half are jet-black. Unsurprisingly, some parts showed minor surface erosion, particularly the centres and other smooth areas. The effect on the assembled and stickered puzzle is a subtle matte mottling that goes well with the shade variation of the pieces.

Prior to this project I solved the kilominx twice without adding lubrication and with only a cursory tension adjustment. It was rough and catchy. As I reassembled the dyed puzzle, I thoroughly lubricated it and carefully set the tensions. As a result, it turns very well. I'm very happy with my dyed and stickered MF8 Kilominx.

Well.. I can't seem to upload my photos (it is giving me an error), so here is a link to the flickr set I made, with lots of photos and descriptions. I welcome your comments and questions.

I wonder if perhaps two packs of Rit dye would change things? 30% concentration seems high and 2 hours seems long.

I have a colored plastic MF8 Circe Megaminx awaiting dying. I just haven't had the time for a several hour project (when you factor in setup and cleanup).

I'll video the process and report on the results when I finally get around to dyeing it.

When I dyed my Dioctipoid, I used three heaped teaspoons of Rit in a 25% solution of acetone (total volume about 0.75 litres) and left the pieces in for about 2.5 hours. They all went very black, and the surface was still very smooth. I suppose how effective the dye takes is very dependent on the plastic you are dyeing - there are many types of ABS.

I don't know which of the colours didn't take the dye, though I suspect it is the darker colours. If I did it again, in addition to lowering the concentration, I would consider dying light and dark colours separately.

I look forward to your results. There is not a lot of shared information on dying coloured plastic puzzles.

Finally, I recovered 650 mL of solution, but I don't really know the concentration of acetone (some of the solution evaporated and I added another 125 mL of water near the end). I think I can work it out from the specific gravity.

http://www.hknowstore.com/locale/zh-CHT ... 794bfe07e1

Black available again!

woohoo! I just ordered a black plastic one! awesome