I agree there is definitely nothing better then sanding, priming and painting, detailed models. I try only to use the vapor type, methods with parts that don't have valuable, detail. It's perfect for dyeing my variant of peetersm's, Drooplop flowers.

Acetone's not that terrible, when handle correctly and its all evaporated. I just don't know exactly, what is in the makers. Not to mention the countless poo brains, out there.

Did you try just a straightforward dyeing technique using fabric dye for polyester? I have not tried it on ABS but had good success with nylon. Not dangerous, no loss of detail and black is black.

Using acetone, you're not far off from traditional painting. I'd think plastic paint would give better results (black is black) without unduly dangerous fumes or loss of detail. Paint would give a little bit of surface smoothing, although not like vapor smoothing.

I thought, since I've learned a lot here. I would share the method and results of my experiments. This method should work on most types of ABS plastic, some colored ABS will give different results, compared to natural white. This method also smooths the part. So care must be taken so you don't lose precious, detail in your model. Repeating this method will make the ABS develop more color.

"Warning this method could be hazardous to your health. This should be preformed in a well ventilated area. Wear gloves. Put down paper for any spills. Always wear protection glasses and clothing you don't mind ruining"

"Supplies list"

• Protection Gear
  Glass Jars - Various sizes
  Metal wire
  Pliers
  Scissors
  Colorful Permanent markers "Brand Name"
  "not the cheap ones"
  Acetone
  Distilled water
  Optional air pump, for drying

Step 1: Use pliers to remove the tip and break away the body of the marker to get to its core.
Step 2: Cut both up an put in glass jar.
Step 3: Pour Acetone in glass jar.
Step 4: Add distilled water.
Note: Different ratio's of water and acetone will give slower or faster results, when dipping part. A part with a lot of detail will need to be done slowly like 80/20% = water/acetone. All the examples provided are straight acetone and permanent marker.
Step 5: Secure ABS part with wire.
Step 6: Dip the part in solution.
Note: If using straight acetone. Only dip the part for a few seconds at a time and let it evaporate, before you dip it again. Acetone reacts, slowly and for awhile, keep that in mind or you will melt detail from your part. I use a air pump to help dry the part faster. Plus you can dip in other colors without it ruining them.
Step 7: Repeat dipping.
Note: The color gets deeper with more dips.

This method can definitely be improved upon. It's not the best. But some things can't be sanded, primed and painted. For example this method can be used to dye, Super flowers (drooloop flowers) Thingiverse 240158. Below is natural white ABS dyed with red permanent marker.

Different colored permanent markers give different results. Most will remain the same color. For example "Black" when mixed with acetone, dyes white ABS plastic, purple. You can mix the colors. Its kind of like dipping Easter eggs. Below is an example of what happens when you dip in different colors and use an air pump to dry, in between. "The original color was blue"

Note: thin parts become more flexible and are less prone to crack as the acetone melts the layers together and seals in, whatever is in permanent marker.

"A few things I haven't tried yet"

• Painting with it - need brushes
  Paper towel evaporation method -maybe the permanent marker will get carried in the drops of vapor and be deposited on the model, slowly?
  Heating it
  Other types of Permanent markers
  Better dipping holder - Pin/needle soldered to a piece of wire

Well, that is about it. If I try or remember anything else. I will update this. I hope you all enjoy. And please stay safe, take the necessary, safety precautions if you are going to use this method. I don't want anyone losing and eye or dying of chemical asphyxiation or dyeing their skin a different color or causing an explosion etc... etc...