Pixiq

Step 1: Preparation- Inverts
First, you need to make a digital invert in Photoshop or like program, like in this image below:

You will need fabric with cyan embedded in it although you can get at:
http://www.blueprintsonfabric.com/ (To learn more about changing the colors, and making your own cyan solutions, see my new book, Digital Image Transfer. )

Let's suppose you want to do this outside. I use plywood as a base, with a digital negative on top of the cyanotype fabric and then coverthe fabric and negative with a pane of glass, to offset movement should there be wind. You can also make a support base by taking fiberglass insulation board (available at any hardware store), foam board or Styrofoam board (available at any art supply store). Either of the latter two can be easily cut to size with a razor blade or Xacto knife. Even corrugated boxes will work as long as they are clean and flat.
Note: Plan the design ahead of time so the fabric is exposed to indoor light as little as possible. Try to complete set-up within 15 minutes. Most important is to secure design (digital inverts, natural designs (such as ferns, leaves, etc.) so that they will not be blown off.  As well, if the sun is not directly overhead, you may need to prop the board at an angle (see illustration). Note: T pins are pressed against glass so support board can be placed at an angle if needed. Prop the support board and pined fabric perpendicular to the sun for best exposure as illustrated below:

 Step 2: Sunlight is preferred over UV light by many unless you create a designated box or have a machine for exposure (more on this later). If you want to find out how to create your own lightbox, I have detailed that in my new book, Digital Image Transfer: Creating Art With Your Photography.
 

Note: Do not move your blueprint during this time, as movement will cause blurring. Prints will be overexposed if they are left out for more than ½ hr in hot weather. Underexposed prints may result from leaving out for only 2- 3 minutes. I have had the best success leaving the prints outside for approximately 15-20 minutes depending on the temperature. In very hot weather, 5- 10 minutes is more than sufficient. See table below.

Note: Timing for Sun Exposure: The ideal temperature is 65-75˚ F, printing between 10 AM and 3 PM., when the sun is directly overhead. When the temperature is above 80˚ F, decrease the exposure time; when below 60˚ F, increase the exposure time.

Hot, summer days – 5-10 minutes
Cool, bright spring days- 8-15 minutes
Cold, clear winter days- 15-20 minutes

(Heavier fabric needs more exposure time)

Developing, Fixing, and Drying the Blueprint
If you have exposed your blueprint outside, move it indoors after sun exposure. Remove your invert (if using a digital invert) and store. Varying degrees of green or blue might indicate partial exposure to the light. This can create an interesting effect.

 Step 1: Next, you need to thoroughly rinse your blueprint in water. Make sure to wear gloves when agitating in sink or developing tray. (If using sink, make sure it is free of any chemicals.)  
Hint: to pump up the whites, you can add a few caps of hydrogen peroxide or bleach.  Continue to rinse the fabric under water until the water runs clear and no longer seeps green from the cyan.

Step 2: Small prints can be dried on newspaper or paper toweling- if the drying area has any blue on it, then the blueprint was not completely rinsed clean. Larger pieces can be hung on a clothesline or you can use a hairdryer to speed up the process. You can dry approximately 6 yards in a conventional clothes dryer:

Cotton- high for approximately 30 minutes
Silk- low for approximately 15 minutes

Have fun and as always, light on ...