Topic: Ysart Bros Paperweight

[mhgcgolfclub]

I thought that this was most likely one of the Ysarts Bros, but have been wrong before so any confirmation would be much appreciated .
Amethyst mottled base.
Diameter 3"

Thanks Roy

[KevinH]

Hard to say.

A neatly finished base is not often linked to the Ysart Brothers period, but there are examples . But this item could also be from the Vasart Ltd years.

The only way I could tell the difference is to use a shortwave uv light ... where a Grey colour would be Ysrart Brothers period (or earlier) and a Blue colour would be Vasart Ltd. (The year of change of the glass batch is believed to be 1956.)

[mhgcgolfclub]

Hi Kevin

Thank you for you reply .
With my normal uv light the paperweight does glow exactly the same yellow / green as a early Paul Ysart paperweight I have.

Thanks Roy

[KevinH]

Standard longwave uv reaction (green = probable use of manganse as the decolourant) is of doubtful use in determining the period of weights in respect of most of the "Ysart periods", and also including the whole of Vasart Ltd and Strathearn production up to 1980.

There are variations of "green" that can be determined but so far, I have been unable to positively confirm the idea that all "early Ysart" (usually meaning pre-war) work shows as a "bright yellow green" under longwave uv. Some may do, some may not. If I am wrong about this I will have to seriously reassess the bulk of my many Paul Ysart weights that I currently categorize as "1930s".

(The 1970s work of Paul Ysart stands alone in  this type of analysis as it used a batch which I believe was boroslicate based, and therefore does not fall into the usual uv reaction for "soda" / "lead" batches).

It is only with shortwave uv light that a (99%) positive separation can be made between "Pre-War" / "Ysart Brothers" and the "Vasart Ltd / Strathearn" periods. But even then only because the former used a "soda glass" and the latter a "lead glass".

[mhgcgolfclub]

Thank you Kevin for all the extra information and sorry for the late reply.

Roy