Perfect Printing Stamp On Chairman Mao First Day Cover?

I would like to say hi to everyone in this stamp forum once again and I am free right now from now onward.I have questions and need help from the experts to identify this chinese stamp on this chairman mao first day cover.I would think the left first day cover is with perfect printing stamp compare and the right first day cover is without perfect printing stamp showing on the scans below.It is because the left stamp has a darker shade than the right stamp especially the face,neck and hands are more orange than the shade on the right stamp on both first day covers when compare with each other.Beside that,the postmark and also the white cover have better looking as perfect condition on the left first day cover than on the right first day cover especially the shade like what I can see it clearly.There is also no brown or white spot appeared on the left stamp but there is a white spot on the right stamp and I have compared the left stamp with more than one hundred copies of the similar stamps but none of the stamps is without brown or white spot like on the left stamp on the first day cover.I really have no idea why the left stamp is with perfect printing but not the right stamp and I would think the left stamp is with perfect printing is probably due to first printing and the right stamp without perfect printing is the last printing at the factory during that period.The postmark and first day cover are also due to first things ever finished over there on the left first day cover than on the right first day cover which finished last by the workers at the same place.


The left first day cover with perfect printing stamp looks very interesting to me and I always look at it.I need help from the experts to help me to identify why did the left stamp is with perfect printing but not the right stamp and give me the personal opinion and explanation for both stamps.I am not a chinese stamp expert to be honest and hopefully the experts can help me,your help is always apprieiciated by me as usual.I will get back to you as soon as possible after your reply in this forum.Please refer to the scans below and let me know what you think.Thank you

Nice FDC's!

I agree that the left FDC looks better.

These are all simply color misregistration and quality control issues, but it is next to impossible to give you the exact reason each of these problems occurred and when they occurred (early or late in the print run).

These types of stamps are usually printed in a single run. Problems could have occurred anywhere during the run (near the beginning or near the end). It is unlikely that the FDCs were made from an assortment of packs from both the beginning of the print run and the end of the print run. Not impossible, but unlikely.

The problems you noted are very minor, and well within the tolerances and specifications of the printer. This applies to both the stamp, the envelope, and the cancel.

My non-expert opinion.

Khj,

Yes,the left first day cover with the stamp are certainly look better than the right one there.My thought is the left first day cover was due to first printing or the shade is not fading but the right first day cover with the stamp is last printing or the shade is fading after so many years gone by,not sure about the colour misregistration and quality control issues just like what you mean above there but I am happy to look at it.Thank you