Today a friend of mine asked how to make Cake flour out of General purpose flour so I did a web search and came up with an "Ehow" answer. It says to subtract 2 Tbsp out of every cup of flour to be used replacing it with cornstarch. I should mention that it says to sift the flour first before counting cups. I thought I would find a Lbs/oz's formula for him to use but there's no mention in either of my textbooks (Professional Chef- CIA nor Professional Baking- Wayne Gisslen) of doing this. I use the flour with the correct protien level in my products and seldom use GP or AP flour. Anyone ever done this? Is there a formula in weights that can be used?