
A suggestion is to print inside the cover various information:
 Filter Factors for commonly used filters
 The arithmetic for using filter factors
 Bellows extension factors and the math for figuring it out
(Perhaps you could put a square shape on the cover that could be put in a scene just like the Calumet tool and include the math for measuring it on the ground glass to determine the extension exposure factor.)
 Reciprocity factors for commonly used films
 Arithmetic for combining multiple factors
That would save having to look at multiple sheets of paper blowing in the wind and would make the booklet very useful in the field.