Remember those heavy, Venetian glass paperweights with little glass flowers trapped inside sitting on lacy doilies? They seem to be a fixture in our grandparents’ or even great-grandparents’ homes. I saw a reference to using a fused glass casting method to recreate this style and I had to try it.
First off – I had to buy a ceramic casting mold (a bowl to create the dome shape) and some glass millefiori. The millefiori manufacturing process is fascinating and I highly recommend looking for a YouTube video illustrating it (but more on that another time). As usual with fused glass molds, be sure to apply multiple coats of kiln wash before filling the mold with glass.
Now begin to fill the mold with glass. I started with a thin layer of clear glass frit.
Then I began to lay out a random assortment of multi-colored millefiori. I wanted a single layer that would dominate the final paperweight.
Another light sprinkle of clear frit to fill in some of the gaps…
and I moved on to filling the entire cavity with pieces of clear glass, often called cullet. The glass should be larger than typical frit. All those random extra pieces of clear glass you had from previous projects? Put some in a paper bag and wail away with a hammer. Besides relieving any frustration you may have, it’s a great way to recycle your glass and create cullet. The more well behaved/well-controlled artist may choose to use glass snips to create small pieces instead.
Whatever your temperament, pile this glass into the mold until it extends an inch or so above the rim.
This goes into your glass kiln, propped up on stilts to allow for better airflow. Treat this cycle like you would for a full fuse, although you will want to hold at your max temperature longer than normal to make sure all the glass has melted – a full cast process. I went to 1460F and held for 30 min. Follow your normal full fuse cooling cycle. Allow the fused glass to sit in the mold for a day after the fusing process! This is a very thick piece of glass and you don’t want to accidentally thermally shock or stress it. (I have not had a problem but this warning seems to be everywhere on the internet and we always believe what we read on the internet right?)
When the mold and glass has cooled, just flip the mold over and out pops a domed paperweight. The bottom may have a few sharp bits which are easily ground off. I thought I was done at this point and I probably could’ve been.
But damn my inquisitive nature, all the warnings on the internet said I needed to fire polish and further anneal my glass to prevent disaster later on. It’s only time and the electrical bill right? So I popped my paperweight back into the kiln. It sat on kiln paper without any mold to force the glass to behave itself.
Since this is really thick glass, more than 1.5″ at height of dome, I ramped up to 1350F at the slow rate of 200F/hour. I then held it for 5 minutes followed by a quick cool to 900F. What’s a quick cool – it’s the infamous AFAP (as fast as possible). Stop the heating elements and open the kiln door briefly several times until the temp gets to ~1200F. Continue to let it cool without added heat until 900F. Then the mother of all anneals should occur – hold it at 900F for 4 hours before shutting the kiln down. Obviously, you have to wait until things get below 200F to open the kiln back up, see the results, and pull out the finished paperweight.
I will admit to being nervous about putting my beautiful ball of glass back in for this fire polish and anneal. What if everything melted and I ended up with a thin round plate? That would have definitely happened if I had held it at high temperature long enough. In my case, the glass dome did smoosh down a little bit and the overall diameter increased slightly. But it was shiny and brought a smile to my face.
I’ve already got 2 more paperweights in process playing with color designs other than using millefiori. Stay tuned to see how those turn out