With Duke Cuan wining crown for Signy the idea of doing a double headed roman cup or flask was born. With Her Royal Majesty Signy ruling just 6 month after her sister Countess Thora, I thought the double headed cup or flask would be fun and cool.  I tried to copy the sisters facial features and much a possible and added the Atlantian shell crown to their heads.

Head shaped vessels are most prevalent in the first to fourth centuries during the Roman Empire, though some date earlier and later. They are said to based on clay cups and jugs from the early first century. There were head cups found the ashes of Pompeii.  The subjects of the head vessels in period where dictated by consumer demand, deities and mythological creatures are most common.  The 2nd most popular are ethnic foreigners with distinct features.

These cups and flask were mold blown in where the mold was made out of 2 parts with seam going through the hair. The height of the head was 10 cm by 8 cm.

Process.

Making the positive.

At 12th night the royal sisters allowed me to take phots of them standing back to back.

From this photo I started to make the positive out of clay.

Getting the shape of the cheeks, nose, chin and eyes correct on both side of the positive took some time. Also trying to keep to the size of no bigger than 10 cm of wider than 8 I kept a not card near with the size on it to make sure I was not getting to big or too small.

After consulting with Thora at Ymir and fixing the nose and working on the them more I added the sprue to the top of the head so that there was a definite bottle top and removed the undercut of the chins so that there was not a large empty spot that the glass would have to flow around.

Making the mold

Once I had a positive that I was OK with.  I started to make the mold from plaster.

I let the positive dry somewhat so that it was a different consistency from the rest of the clay that I was going to use to bolster the positive as I poured the first half of the mold.

I then build a box around the positive and pillow using 4 boards and clamp, I put clay inside and outside of the box to seal the corners and to seal any gaps that plaster could flow into around the positive.

I then mixed the plaster and filled the box . Notice this process was done in the grass outside because if the seals do not hold it is a mess. The first pour on the mold went smoothly.

I removed the sides of the box 24 hours later. Flipped the mold and removed the pillow from around the positive.

Then I did a little clean up work and put a slip layer on top of the positive and the mold. A slip is a slurry of clay and water that is finely mixed so that the 2 sides of the plaster mold are able to be separated.

Boxed in the bottom half of the mold and poured the 2nd part of the mold.  This time the seals on the box were not as good and one full pour went on the ground around the edges. So I resealed and repoured before it could truly set.  This cause some of the mold to be weak and break off in the first few blows but since it was not any of the detail of the mold it not an issue.  The pictures below are all taken after the 2nd repour as there was not enough time to pick up the phone for more photos when it was coming out of the box.

After the mold had set a little I marked the 2nd pour on the back and waited 24 hours until opening the box and splitting the mold.

I then cleaned the clay out of the mold and let it site for about 2 weeks to dry.  After sitting then I used a metal coat hang in a drill to drill air holes in the mold so that air can escape as the glass fills the mold.

Finally the mold was sprayed with graphite as a resist.

Blowing glass into the mold.

The first  try at blowing glass into the mold I did a single gather of glass blew a bubble then gathered over it and stripped some of the glass off. Then started to blow a bottle stretching the neck until I got the neck of the bottle so it could fit into the mold.   This resulted in too much glass in the mold and I ended up with an amorphous blob that kind of looked like a head.

The mold was damaged in the eyes on one side. I resprayed the mold and waited until the end of the evening to try again.

The 2nd try I did a gather and a half of glass, then put the bubble in and started to make an onion bottle shape using gravity to stretch the neck of the bottle. The neck of the mold is narrower than the pipe so the neck has to be stretched before blowing into the mold.

This time I came out with a good detail on the whole cup. The eyes on one side of the mold lost the detail work and were attached to the glass when I finished blowing the mold.  They will be re carved out and detail added back in for more blows.

After coming out of the mold I redid the jack line and flattened the bottom more.

We then transferred the cup to a punty so I could open the mouth.

It took several re-heats to get the mouth opened.

After coming out of the mold I redid the jack line and flattened the bottom more.

We then transferred the cup to a punty so I could open the mouth.

It took several re-heats to get the mouth opened.

Thanks to Master Nickoli for the pictures of the finished product and for photos while blowing.

Sources

Roman Mold-blown Glass: The Toledo Museum of Art. The First through Sixth Centuries by E Marianne Stern

Ennion: Master of Roman Glass By Christopher S. Lightfoot; With contributions by Zrinka Buljevic, Yael Israeli, Karol B. Wight, and Mark T. Wypyski

CMOG web site