Roseville bowl with extra number

My Roseville 389-6" bowl has an extra number (18) etched into the bottom. Does anyone have an idea as to why? It looks like it is part of the original piece. I tried to post a photo but it said the file was too large. It is just the number 18 hand engraved into the bottom.

 

Here is a pic

 

I can't find my Roseville book at the moment, but if I recall correctly those marks were made by the people who produced the piece. Each person who handled the item made their specific mark, so the piece could be traced back to that person in case of production problems / errors on down the line.

My guess would be the incised 18 was from the person who molded the bowl. And the green 2 was most likely from the person who applied the glazes.

If I'm incorrect, hopefully someone else will provide the right info.

 

Thanks. That is kind of what I was thinking except I saw the glaze marks on the other pieces, but I did not see any marks inscribed on any other pieces. The glaze marks are on Roseville pieces, but not the inscribed numbers. Thank you so much for your time and interest. Maybe this was a particular group where they required that. I don't know. I haven't seen any other marks like this as I have scanned the internet.

 

Hello and Welcome - the following quote comes from Sharon and Bob Huxford's. "The Collectors Encyclopedia of Roseville Pottery - First Series", pg. 24.

Other letters and numbers found in ink or pencil on the bottom of many pieces of the commercial art lines were used to identify specific workers doing a specialized job, such as moulding, cleaning, decorating, or inspecting. These were simply an aid to quality control.

Although it doesn't specify etched numbers I believe those marks also served the same purpose.
Don

 

Thank you so so much!

 

Books vs. Internet ... Books win !!!!

 

Haha! No doubt. I looked everywhere for this answer that I could think of on the internet and just couldn't seem to get an answer. It is very kind of you all to take time out to try to answer my question. I think I have a satisfactory answer.

 

stick around....there's more fun and learning to be had here !!!!