DISCLAIMER: Inhaling iodine vapors can cause severe pulmonary irritation and pulmonary edema. Use with extreme caution.

1. Prepare necessary materials and setup latent print photography equipment prior to processing item. 

2. Select an application method.

Fuming Cabinet: Place item in a fuming cabinet with a container of iodine crystals. Gently heat iodine crystals and closely observe development.

Fuming Gun: Insert iodine crystals, filtering wool and drying granules into the glass tube of the fuming gun. Gently blow into the gun, warming the crystals and releasing a vapor. Continue blowing into the fuming gun and direct the vapor onto the item via attached tubing. 

3. Ridges will develop a brown color temporarily. Remove the item when sufficient development has occurred. 

4. A 1% aqueous brucine solution may be used to fix the developed ridges onto the item. However, this process may inhibit subsequent processing procedures. 

5. Capture any developed ridge detail immediately using 1:1 photography.