What are the common reasons for OPAP to object to patent drawings?

OPAP may object to patent drawings for several reasons, including:

1. Line quality issues
2. Missing lead lines
3. Excessive or non-English text
4. Incorrect margins or paper size
5. Improper figure labeling
6. Illegible photographs
7. Unauthorized color drawings or photographs

For example, regarding line quality, MPEP 507 states:

OPAP may object to and require corrected drawings within a set time period, if the drawings: (A) have a line quality that is too light to be reproduced (weight of all lines and letters must be heavy enough to permit adequate reproduction) or text that is illegible (reference characters, sheet numbers, and view numbers must be plain and legible). See 37 CFR 1.84(l) and (p)(1);