community of dyers

Judy, I've did spraying too, but that's not healthy option. I'd suggest to thicken the dyes and use small foam roller to apply it over the stencil. We did it in textile school and you can mix dyes on the roller and make use of this effect in combination with the stencil.
There is use of roller and stencil (not with MX, but doesn't matter)
roller and stencil

It's certainly important not to breathe droplets of dye, which is just like breathing dye powder.

I think it's safe enough if you wear a dust mask that fits well enough that you don't breathe unfiltered air in from the sides.

I always do my spray-dyeing outside, standing on the upwind side of my work. Indoor spraying would require a spraying booth to contain every drop of dye. The spraying booth could possibly be based on a large cardboard box, though commercial ones with extractor fans are better.

Below is an ad with an example of a spraying booth. Evidently the air flow is strong enough that the front panel can be left uncovered. For the homemade cardboard box version, I'd want to have an opening just large enough to admit one's arms, with clear plastic covering most of the side that's open in the commercial version....

-Paula

Paasche Hobby Shop Spray Booth

Rugged and compact, this portable spray booth features galvanized metal construction for easy cleaning and durability. Working dimensions are 24 inches wide × 18 inches high, perfect for small ceramics and models. It provides approximately 80 to 100 LFM air movement. Uses a carbon and fiberglass filter system, intended to remove larger particles from the air, but will not remove ALL hazardous materials. When spraying harmful chemicals, exhaust should be vented to the outside. Includes a 1 phase, 60 cycle motor. The booth is equipped with 3-wire cord, and requires a grounded 115V power source. It weighs approximately 42 lb (19 kg). $339.00

Thanks all for your input! I did get a chance to do some experimenting recently, using a foam brush to daub on the dyes through the stencil I was using. Here are some of the results:

Unthickened dye used here - it bled a little

Thickened dye used here - no bleeding

Here, I overdyed the first stencil to see how it would react - no major problems or change other than the colors

But look at how the overdye reacted on the thickened dye stencil... almost looks 3-dimensional!

Here, I created a mask with freezer paper ironed onto the fabric, then stenciled with thickened dye in the unmasked area... I really like how this came out!
So, now I just need to try this technique on a shirt to see how it works... I am pretty confident it will be something I can use with success, and I like that I can daub on the dyes instead of spraying.
Judy

tiedyejudy's shop
http://www.tiedyejudy.artfire.com
blog: http://hippiewear.blogspot.com
"Life without tie-dye is waaaaaaaaaaaay dull!"

Judy,
I've tried variation of thickened soda solution on the fabrics. It was great against bleeding. Have you printed on dry fabric?

Hi, Jaja. Yes, I was printing on dry fabric that was pre-soaked in soda ash solution. My standard mixture is 1 tsp soda ash per 1 cup water for the pre-soak. How did you vary the soda solution when you printed?
Judy

tiedyejudy's shop
http://www.tiedyejudy.artfire.com
blog: http://hippiewear.blogspot.com
"Life without tie-dye is waaaaaaaaaaaay dull!"