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Glass Identification - Post here for all ID requests => Glass Paperweights => Topic started by: cxgirl on September 16, 2015, 04:08:11 PM

Title: St Louis Upright Bouquet Seam line?
Post by: cxgirl on September 16, 2015, 04:08:11 PM
Hi,
I was taking photos of this paperweight and a line shows up in some of the photos - would this be a seam line? Is this considered damage? I can't see it when I look at the weight but it shows up in the photos so it must be there.
Any information appreciated.
thanks for looking
Mary
Title: Re: St Louis Upright Bouquet Seam line?
Post by: KevinH on September 16, 2015, 05:14:59 PM
I think the line is simply minute air bubbles or a constant, tiny line of air at the connection between the twist cane and the main coating of clear glass for the dome.

The twist cane itself is coated in clear glass to support the coloured element and when the next layer of clear is added, air can get trapped all along the join.
Title: Re: St Louis Upright Bouquet Seam line?
Post by: Sach on September 17, 2015, 04:38:35 PM
This is just an artifact of the manufacturing process.  The cane used for the torsade most likely was not made from the same melt of glass as was the dome of the paperweight.  This can result in minor differences in the optical qualities / index of refraction of the clear glass used.  This is especially true in older work where the batch materials were not as precise in chemical content and the systems for measurement and mixing were similarly less precise.  When such a difference exists it is visible in the way seen here, light is refracted as it crosses the line of transition creating a visible "seam" where no gap or air is present.
Title: Re: St Louis Upright Bouquet Seam line?
Post by: cxgirl on September 18, 2015, 07:11:57 PM
Thank-you both for your replies! I haven't seen something like this before. Would this have been considered a 'second' or is this something that is acceptable as part of the process of making paperweights?
Mary
Title: Re: St Louis Upright Bouquet Seam line?
Post by: KevinH on September 18, 2015, 08:55:35 PM
Not a second.  :)
Title: Re: St Louis Upright Bouquet Seam line?
Post by: cxgirl on September 19, 2015, 03:41:48 AM
Thanks again KevinH!
Mary