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Some info on Lead in Glazes

Have you seen the TikTok or Reels videos that show a person going into their local thrift store and checking plates, bowls, and cups with a little marker for lead? When they mark the piece if the mark changes color it shows that there is lead in the piece and they claim that it shouldn't be sold and they offer to get rid of it for the thrift store?  Let's talk a little bit about lead in ceramics and in glass.  Historically speaking lead was added to the components of the glaze as a flux.  Adding the lead meant that the silica that was used to form the glass part of the glaze meant that the glaze could melt at a lower temperature than without it.  This was good because it meant the kiln did not have to get as hot to melt the glaze on the pieces.  In addition, if a artist was using a low-fire clay then during the glaze firing it did not have to get as hot, and potentially over-fire and melt the clay. Lead was also added to glass for the same reason that it was use...
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Art Materials are Expensive, Yo!

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 So in keeping with the making of plates for the series that I'm planning!  The week ended with 6 plates drying last week, and drying this week all under a flannel backed tablecloth.  On Monday, a little clean-up happened on them and set them back to slowly dry (in case that was the reason of the cracking from the last two pieces).   On Friday, impatience got the better of me, and all 6 went into the kiln! One was probably a little damper than I would ordinarily put it in, but again, impatience! While these pieces were going into the kiln, a thought hit me, and so I grabbed the two cracked plates and added a Clay Mender product by Mayco.     I've used this product before, though I prefer making my own paper clay for mending pieces - I've found that paper clay works better for fixing things in the Greenware state.  Paper clay discussion is for another time! :-)  Mayco makes this product, and Amaco makes Bisque Fix - which is a great produ...
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A Lesson (Hopefully) Learned

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 Well, this is a bummer.  This photo was posted a few days ago on Facebook.   I knew going into the firing that the plate on the left had a crack, around the ridge but the other plate was completely ok going into the kiln.   After the initial sting of finding them cracked,  I was off to find a reason why this happened and how to keep it from happening again.   What appears to have happened to the first piece was either there was a bit of water left on the piece that settled into the spot where the lip rises and that moisture created a spot of unevenness in the drying process.   For the other piece, that crack appears to have come from uneven heating in the firing.  I had the plates stacked, which I've done many times stacking pieces: tiles, bowls, smaller pieces inside of others, but I think somehow there was an uneven heating causing this crack.   I completed this firing in the test kiln which is a small kiln that ha...
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Teaching a New Class

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  Yesterday, I taught a new class on Idea Generation.  The class was based on a system of steps that one could take when looking at:  a piece of art, a piece of music, embroidery, recipes, games - basically just about anything in the arts and sciences, and turn it into a piece of work all of their very own.  There were six people that attended the class, including some SCA friends, as well as a young member of the SCA as well as someone who just joined the SCA three days ago and this was their first event. Honestly, this was an incredible turn out, being as though the class was not listed with my name or a description of what the class was about. In addition, it was listed as tentative due to uncertainties when it was time to register the class!  We had a great time, the class lasted a little less than 45 minutes - which was the target time that I was aiming for!  Overall a good experience - I'm glad I had such interest in the class.  I might take this...
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Molds

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 Thinking about historical potters, it struck me that there had to be some uniform way to create plates or bowls so that they were the same (or nearly the same) size and dimensions each time or if they were made by different potters in the workshop.  What is the easiest way to create something to be consistent and uniform? Use a mold of some sort!   Today, I made two plates that were the same size and shape through the use of a drape or hump mold.  This is a mold where a slab (flat sheet of clay) is draped over the top and shaped to the mold.  Piccolpasso would have used either a plaster or wooden mold in his workshop. These would have been most likely purchased from another shop, especially the wooden molds.   I could have chosen to use a plaster mold, however, I know that plaster can chip and become less durable over time.  If plaster gets into the clay it can also make the clay explode.  I chose to use a wooden mold in order to make t...
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Maiolica Firing Temps vs Current Practice

 I was just about to go to bed - the doggo needed to finish dinner - so I grabbed a new book that I just got in the mail (Thank you Ebay!) and opened it to a random page.  Here's what I know:  Traditionally low-fire ceramics are fired to a higher temperature for the bisque (first) firing and then a lower temperature for the glaze (second) firing.   Bisque (First Firing)                                                  Glaze (Second Firing)       ~1915F                                                                           ~1890F or  ~1830F This is done primarily for two ...
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I'm Torn....Historical vs Different Skills

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 I'm doing some digging into Maiolica research.  I've read Piccolpasso's three treatises on Maiolica a couple of times, and I'm going to go back and dig into it again as both of the last times I've read it, I've come away with different and more information. Each time I've found things that have lead me towards different research and rabbit holes to fall into as well!  One of the things that Piccolpasso talks about in his treatise is that the ceramics were created on a potter's wheel that would have a wooden mold attached to it in order to make the plates or bowls.  This makes complete sense to me, as Piccolpasso was living in the area of the Castel Durante potteries.  These potteries were making mass quantities of pottery for different households, castles and even for the Pope. That said, the artists needed ways to cut time down on making the pieces, and using a mold in the creation of bowls and plates and other dinnerware, makes it considerably easier ...
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