As I learn to properly size my signature pics and pics within my message body, it has become evident that there we are using multiple rectangular sizes.

Here is what I've found for signatures:
Length x Height
100 x 65
100 x 66
100 x 67
100 x 72
100 x 75
120 x 90
110 x 82
120 x 90
150 x 105
154 x 146
200 x 99
...

For pics within the message body:
Length x Height
380 x 288
432 x 324
...

Yes, there is a question here. Are there preferred sizes or what is the scalability ratios (Up or Down), i.e. the golden rectangle that best shows jpegs. Of course, I assume this must be all related to the size of the original pic.

Excuse my "pic-challenged" question, but when I get CHOIREBOY, I want to post my best.

SMKKVK - Keeper of the List for CWFFC

 

FYI: A Golden Rectangle has sides measuring 1 by 1.618.

(Just trying to up my posts towards the next shift)