Thanks to PatentDraftsman for starting this discussion.
I have one observation to add that all attorneys may want to consider and all draftspersons may want to use as encouragement for attorneys to file formal drawings when the application is originally filed.
Recently the USPTO has implemented a slightly different image scanning process which captures graphics ONLY in black and white, not greyscale which was only used for a short time period, but no longer uses. And even if graphics look like they may be greyscale, look closely and you will notice that what your eyes see as greyscale actually is just stippling (pixellation of black dots).
So what does this mean?, what impact does the purely black and white scanning have? Any drawings which are submitted that are not line drawings have a high chance of being seriously distorted. In particular, any screen captures and digital images which are filed as informal drawings are likely to turn into entirely black blobs which provide the Examiner little or no opportunity to fairly and accurately examine your application. (Check some of your PAIR drawings, you might be surprised that some are completely useless.) And do not necessarily expect to receive a Notice to File Corrected Papers from the initial examination office, because they make their determination based on the actual paper documents which are filed, not the scanned documents. Which means that the initial examination office does not know what the scan will look like, and does not typically issue a Notice to File Corrected Papers based on greyscale drawings, even though the scan of those greyscale drawings may not reproduce correctly.
Unfortunately, not all Examiners will follow MPEP guidance and immediately request corrected drawings. Some Examiners will proceed with the black blobs on the electronic file wrapper and presume that what they have in front of them is what you provided for them to work with when examining the application. This can present a serious problem when an examiner proceeds to examine a case without the benefit of drawings which can be interpreted. And then you have the problem of establishing that the corrected drawings do not introduce new matter. The Examiner has to request to review the originally filed materials so he/she can see that the corrected drawings actually reflect what was originally filed, but turned into black blobs when scanned.
So, a word of caution to anyone who ever files digital images or screen captures. If the informal drawing has areas of similar brightness, regardless of colors shading, etc., the drawing should be prepared as a formal line drawing before filing.
Alston & Bird LLP