PB103 quatrefoil cup - still chasing the grail

My first quest in my recent ceramic class was to make a quatrefoil cup. I threw three but squished two of them because the proportions just didn't look right. My final one still isn't perfect but it was the best of the lot and the shape visually pleases me.

So what is a quatrefoil cup? A quatrefoil cup has a rotund body, which cinches in slightly then flates out. The lip is pinched so as to form four lobes. The lobes take up slightly less than half the cup. There are a number of quatrifoil and cinquifoil extant items available in museums. My favourite is posted at the bottom of this entry because the Swiss National Museum doesn't create independent linkable pages for their items.

Quatrefoil Cup. 9cm tall. 15th century, Cheapside, London.

British Museum. Museum no. 1899,1005.3.

My first attempt at a quatrefoil cup was my third ever thrown item. I threw it at Pennsic in 2019 and it's details can be found here. My next attempt at a quatrefoil occured during day 1 of a 5 session class. I'm still learning about how to determine the stability of clay and how to intuitively feel when it's been pulled enough. I started using PB103 which is a basic white clay. It's reasonably dense and can sustain a lot of height on reasonably thin walls.

There are three main things wrong with my quatrefoil. First, height: The original is 10cm wide and 9cm tall. My cup is taller than it is wide, resulting in more vase overtones. Second ratio: the original had the quatrefoil lip flaring out from just over a half cup. Mine is about the top third of the item creating a 60 degree angle rather than an 80 degree angle for the lip. Finally glaze: I used a matte green glaze on the base of my cup and a clear internal & over the lip glaze. I should have reversed this, glazing the inside and lip green and then sealing the lot with a clear glaze over everything.

Interestingly, the colour variant in the glaze of my cup is due to the firing process rather than a deliberate attempt. I'm not sure if this a slightly temperature change or a slight oxidisation change both could be caused by the bulbous nature of the cup.

Breiter Henkel mit seitlich eingedrückten Rundflächen; enger Hals. Herstellung: Zürich. 1400 - 1500. Herkunft: Zürich (ZH), Haus zum Johanniter. 23,4 cm. Ton, glasiert. (Broad handle with indented round surfaces; tight neck. Production: Zurich. 1400 - 1500. Origin: Zurich (ZH), Haus zum Johanniter. 23.4 cm. Clay, glazed.) Swiss National Museum. Item no. LM-24622 or possibly DIG-4681