I printed out Frank’s linked page and have spent some time examining the different puntys and treatments shown.
I am not sure that anything that I can add will necessarily throw any real light on the situation. All my comments are based on my overall knowledge of glass making and finishing and not in any way related to my limited knowledge of Monart and Vasart. Most of what I have to say, however, is just conjecture.
Perhaps it would help if I begin by pointing out that there are many different ways of preparing a punty. Almost every individual glass maker does this slightly differently. Today’s studios are fairly liberal about this, but even as late as the sixties, factories like Whitefriars were run on the old fashioned hierarchical basis. Some gaffers would make their own punties. Others would expect the punty to be prepared for them exactly to their specification, and used to send it back in no uncertain terms if the size and profile was not satisfactory. This might well have been accompanied with a quick burn on the assistant’s arm from a hot iron. Think David Attenborough and the gorillas: the gaffer was the silverback!
There are different ways of making punties, for different purposes. The size and style will generally be an individual’s preference, but there are a few general rules. The type and size of the piece will to some extent determine the size and shape of the punty. The punty has to have sufficient surface area to support the full weight of the piece, and the amount of finishing – shearing and opening may also have a bearing on this. Another critical factor is ease of breaking off the iron.
The differences shown in Frank’s photographs, therefore, could simply be the result of different sets of hands on the pieces. It could also be that the more experienced the glass blowers became, the smaller they made their punties. The availabilty of cold working time, as well as suitable equipment and skilled cold workers, could also have had a bearing on this.
The earlier pieces shown in Section 1 show that care was taken to minimise the amount of cold working required. The concave shape of the bases, which have been pushed in with the edges boarded, mean that the pieces should stand up without the necessity for flat-bed grinding. This would diminish the cold working time, but would depend on the punty being applied correctly, and the piece kept sufficiently straight while re-heating, shearing, and opening. You can see in sections 2 to 4 that this didn’t always work. These pieces have had to be centred and/or levelled on a flat bed grinding wheel.
It is difficult to tell once a piece is finished what happened when it was hot and what type of punty was applied. There are two methods that could have been used to apply these punties, and they would both look the same now. The first is to make a necked in punty, which I suspect has been used in the fifth (Vasart) piece. The second is to cast a small pad onto the base of the base and then attach a punty to this. I think this may be what has occurred with some of the items in Sections 2, 3 and 4. The Vasart item in section 5, however, has small chips in the centre of a lightly ground out punty, suggesting that this may have been a cross-cut punty, as opposed to a pad. It could be that by the Vasart days they were more experienced, working faster and more confident of breaking pieces off the punty iron without losing them.
The purpose of a pad is to ensure that when the piece is broken off the punty iron, it comes away neatly. This also works with a necked in punty, where the break off is on the neck of the punty, rather than chipping the punty from the base of the vessel, which is what you do with a cross-cut or hollow punty. It is very easy to end up with a lovely piece of glass with a hole in the bottom unless you get this exactly right, and one way of avoiding the problem is to use a pad.
There appear to be different combinations of cold working treatments and I suspect that these are simply the outcome of the amount of work needed for individual pieces. This would be partially determined by how much levelling would be required and the relationship of how proud the punty was relative to the base. In Section 1, the punties are all below the surface of the outside edge. This means that they only needed to be lightly ground in order to remove any sharp edges. In Section 2, the same applies, even though the piece has had to be levelled substantially. The same for Section 3. In Section 4, however, the punty was obviously quite prominent and it wasn’t considered worthwhile to grind it out on the lathe, since the piece needed substantial levelling to make it stable, so they just ground the punty out on the flatbed, simultaneously flatting the base. By contrast, the piece in Section 5, as mentioned above, seems to have had a relatively dainty punty, that required minimal wheel work, despite the fact that the piece needed grinding to level it.
The chips in the Section 6 pieces again suggest a cross-cut punty, but are not 100% evidence. These do look heavier. They have had to be ground out on a wheel because they were below the surface of the foot, even after levelling.
I hope this helps, but I’m not sure whether this area of research is going to be that significant!