Leaded glass window process, step 10

In step 9 I showed the putty being applied.  I use a horseshoe nail along the edge of the lead to clean off the excess putty.  The above image shows a whiting on the glass to clean the glass, absorb oils from the putty and flux (soldering stage).  The whiting also helps the putty to dry faster.  The bottom panel has whiting on the backside and the top side is clean.