How Magic Becomes Science

Have you ever unloaded a BEAUTIFUL piece from the kiln and thought, “Gee, I wish I could remember how I did that”?

A big part of glaze testing and advancing your understanding of glazes is record keeping. Whether you’re dipping test tiles or glazing your pots, it’s essential to take notes and keep track of your process.

This is how magic becomes science and how those happy accidents become intentional flourishes.

You need to remember the steps you take in as much detail as possible in order to repeat your results. Depending on the glazes you’re using, small changes can sometimes have a big effect on the outcome.

The best way to remember is by taking lots of notes and taking lots of pictures.

We might think we’ll remember what we’re doing while we’re glazing but the truth is, by the time our pots come out of the kiln our memory tends to become more general and the magic is in the details.

In this post, I’ll share all the things I keep track of throughout the different stages of the glazing process. From mixing the glaze to unloading the kiln, there are certain things I pay attention to that help me down the road.

Get Yourself a Glaze Journal

If you don’t already have one, get yourself a glaze journal. It doesn’t have to be anything fancy, just a cheap notebook is fine. You could also use a binder or a sketchbook.

Even scraps of paper lying around are better than nothing in a pinch, but you should have a folder or something to keep them in. They won’t be of any use to you if you can’t find them.

I like using artist’s sketchbooks because the paper is thicker and can easily withstand accidental glaze splashes. No lines on the page, the freedom to scribble and sketch all over the place.

       

This book doesn’t have to be just for glazing. You might have a book that you’re already using to keep notes about the rest of your pottery making process and ideas. If you do, you can use that.

I find it helpful to have a separate glaze section so I can easily find what I’m looking for. In my sketchbooks, I start at the beginning of the book and work forward with pottery making notes and then start at the back of the book and work backwards with glazing notes.

Find a system that works for you and then record as many details as you can while you’re glazing.

What to Keep Track of in Your Glaze Journal

This is a detailed list with explanations. I also created a pdf checklist that you can download, print and keep handy in the studio. The link to download it is at the top and bottom of this article.

Glaze Mixing Notes

▢ The date

Having the date on each entry is super useful when trying to remember how you glazed a certain piece, like that “bowl you gave to so-and-so for her 50th birthday”.

▢ The recipe

You might want a whole section or even a whole different book for storing glaze recipes. But when I make each new batch of a recipe, I write it in my journal along with lots of other notes.

▢ Batch quantity

After writing the recipe down, I batch it out according to how much glaze I want to make. This lets me know how many grams of each material to add to the bucket. I also like to go back and see how much of each glaze I’ve made in the past.

▢ Check off each material before adding to the bucket

I make it a habit to check off materials after weighing them but before adding them to the bucket. This way I’m not wondering if I already checked something off. If I dump the material in without checking it off first and then get distracted, it’s sometimes hard to remember which was the last material I added.

▢ How many grams of each material I physically add to the bucket

I do this when I’m unable to weigh the whole quantity of a material at once. When I’m at work, it’s common for me to get pulled away from what I’m doing. If I’ve only added 375g of the 500g the recipe calls for (because of the size of my weighing container) I write 375 down as it goes into the bucket. Then I weigh out the other 125g and check it off.

Here I couldn’t quite fit 500g of EPK or Gerstley Borate in my weighing container so I marked down how much I weighed first, dumped that in the bucket, and then weighed out the rest.

▢ Did I run out of something and make a material substitution?

Always keep track of any changes you make to a glaze recipe, no matter how small. Maybe you’re only 5g short of a material so you just go with what you have. Keep track of this in case that 5g makes a difference.

▢ Did I open a new bag of a material?

I like to know the dates I open new bags of materials. That way, if the appearance of any glazes change, I can go back and see whether it’s a new material that could be causing the change.

▢ Did anything strange happen while mixing?

Like “uh oh… I forgot to check off the zinc, but I’m sure I added it” or “I completely forgot the wollastonite” or “the gerstley borate was super clumpy” or “a teaspoon of spodumene didn’t go through the sieve.” These details can come in handy for any troubleshooting down the road.

I completely forgot to add the Wollastonite to this recipe when writing it down.

Glazing process notes

▢ Which glazes were used, over and under

This is essential! It might seem obvious at the time but you’d be surprised how easy this is to forget. This is arguably the most important thing to keep track of while glazing.

This is generally how I document my glazing process. It ain’t pretty but it’s useful. I try to include as many details as possible.

▢ New things I tried

Like brushing a different glaze on the handle after dipping, holding the rim in extra long, a swoosh of this here, a splatter of that there. Remember, the magic is often in the details.

▢ Length of time between coats or between inside/outside

This can come in handy when troubleshooting glaze issues. Some glazes don’t adhere well to wet bisque so you’d want to know if you need to wait longer for the second dip, or if you can rule that out as the cause of an issue.

▢ If I counted the length of my dips

Did you hold your piece in the glaze for 3 seconds or 10 seconds? This is really good info to have if your glaze came out too thick or thin.

I dipped some cups in water for 5 seconds first and then 5 second dip in the glaze, up to 1cm from rim. The water was to reduce absorption of a runny glaze.

▢ What’s the specific gravity of my glazes?

If you measured the specific gravity before glazing, write it in your glaze journal. If you didn’t, write that down too.

▢ Spraying details

How many times did the piece go around on the banding wheel? If you know this, you can repeat it next time.

▢ Brushing details

Brushing consistently requires paying attention to how many coats you’re applying. Did you brush in one direction or mix it up? Was the glaze dry before adding another coat? What size brush did you use?

▢ What I’m expecting or hoping the results to look like

Having your process documented and also the result you’re trying to achieve will help you connect the dots when unloading.

If you thought a certain technique was going to result in a certain look and it didn’t work out, it’s helpful to make that connection so you can reassess and come up with another way to get the look you’re after. On the flip side, if you got the result you were after, you need to know this too!

▢ Glazing mishaps

If I had to wipe off a splash or didn’t wipe off a splash, dropped a piece in the glaze bucket and rinsed/started over, glaze started cracking as it dried but fired it anyway.

Here, I dripped the inside glaze all over the outside and wiped it off. I put the piece on my hot kiln to dry before doing the outside glaze.

Outside glaze seemed thick. Had some lumpy bits on the handle.

▢ Length of time between glazing and starting the kiln

Sometimes your glazes feel dry but the underlying bisque is still wet. This can have negative effects on some glazes.

Firing notes

I like to make connections between how the firing went and the glaze results in my glaze journal. I have a different book that I use for kiln logs and keep different types of notes in there.

▢ Did the firing reach temperature or go over?

This is one of the most important factors that affects glaze results. Notice how changes in temperature affects your glazes.

I had to leave the house so I shut the kiln off before I wanted to and the kiln underfired.

In this case, the kiln was too hot which affected certain glazes.

▢ How do the cones look? Multiple cone packs look the same or different?

Many kilns have hot and cool spots and knowing where these are will help you make sense of your glaze results.

▢ Witness cone pack exploded (seriously!)

This has happened to me, I must admit. Always make your cone packs well in advance of your firing so they’re dry! If this happens to you, write it down so you don’t forget!

▢ Issues with the kiln or firing?

Keep track of anything out of the ordinary that occurs during the firing.

▢ Power failure and had to restart

Depending on whether your glazes have already started melting when the power went out, this can affect results. If you can, record the temp the kiln was at when you started the firing again.

▢ Longer firing than usual

Length of firing can affect glaze results.

▢ Fired really fast

A lightly packed kiln can take less time to reach temp, especially if you have a manual kiln. This could affect glaze results.

▢ Kiln load was really full or light

Kiln pack can affect firing length which can affect glaze results.

This was a gas reduction firing that was packed really full. I take even more notes about gas firings than electric firings, all in the interest of understanding glaze results.

▢ Did I program a slow cooling cycle?

This will have a big impact on glaze results.

Unloading the Kiln

It’s important to not only record your processes but also to go back and connect your process to your fired results. As you unload the kiln, read through your process notes and look at the finished product.

▢ Did your pieces turn out as you had hoped?

Highlight any successes so you remember to try them again.

Finally a firing with no drips! Candles work out best when inside glaze is dry before glazing outside.

▢ What was different than expected?

Take note of anything that didn’t turn out how you thought it would.

▢ Do you like the glaze combination you used?

Keep track of this for next time. You might forget and repeat something you didn’t like, or forget something you did.

▢ What happened to that drip?

If you wiped off an accidental drip or left it there, what happened to it? Did it blend in or does it stand out? Do you like it, or would you prefer it wasn’t there?

▢ Was there any crawling or running? Pinholes?

These unfortunate results can be connected to the length of your dips, the length of time between coats and the length of time between glazing and starting the kiln.

▢ What do you want to try or do differently next time?

Kiln unloading time is the best time to write down what you want to try next time you’re glazing. It’s the time when you’re most excited and inspired (or, knock on wood, disappointed).

If you wait until you’re glazing again to think back on your last kiln load, you may miss something and make the same mistake twice or forget something awesome that you wanted to try.

Plus, how often are you rushing to get your glazing done and feeling slightly uninspired or uncreative? Having some ideas planned out in advance takes the pressure off when it’s glazing time.

Baby Steps

This is a long list of things to pay attention to. You don’t have to adopt such a detailed glaze journaling practice right off the bat.

Just start by noticing and tracking a few new things. Even a little bit of note-taking will come in handy at some point. Do what feels right for you.

We all have different methods of working and ways of processing information. I’m a details person. I really enjoy figuring out cause and effect and recording details comes naturally to me.

If it hurts your head thinking about writing all of this down, the next section about photo journaling could be a great visual option for you.

Keep a Photo Journal Too

Ever since I got a smartphone I take photos of my glazing process, not just my fired results. There’s a lot of useful information in the way the glaze looks before the firing, as well as after.

I used to sketch my pots as I glazed them to keep track of the patterns, resist methods, etc. I’m a pretty awkward sketcher but it worked for me at the time.

If you don’t have a camera, I recommend sketching your pots in your glazing journal, especially if you use a complicated glaze layering process.

Sketching out how I want to glaze some teapots.

Now that my phone is a camera, it’s so handy to take photos all the time. I do this in addition to keeping notes in my glaze journal. Sometimes I even take photos of my notes! The more info, the better.

Photos help me remember the process I used and then I can compare before the firing to after the firing. I often learn something that helps me repeat or improve my results for next time.

What to Take Photos Of

▢ How deep is the glaze overlap?

Sometimes I’ll take a photo after the first dip and then after the second dip. If the glazes overlap, I like to know how much they overlap, so I can see how much they move or stay put.

▢ Where are the glaze drips? How do they look fired?

Take a photo of glaze drips, whether intentional or unintentional. Seeing exactly where there’s a glaze drip on a pot helps you find it after the firing. Maybe it disappeared. Maybe it blended in. Maybe it made a nice colour. Compare before and after the firing.

▢ When layering, which glaze was on top?

Having a photo of your glazed piece helps you remember which order you applied your glazes (if they’re different colours) and how much they overlap. Again, it’s good to take a photo after the first layer and another after the second layer.

   

On the left is first layer of glaze, then wax resist. On the right is second, sprayed layer of glaze, resisted by the wax.

▢ How high up was the wax resist line? Did the glaze move at all?

If your glaze ran onto the shelf, this can be useful to know for next time.

▢ Did the glaze crack before the firing? Did that affect the result?

Having a photo of where a dry glaze started cracking will show you whether it affected the finished piece.

▢ Did I accidentally smear the glaze surface before it dried? How did that affect the result?

This is something that’s hard to describe in words but easy to see in a photo.

▢ Were there tiny air bubbles in my glaze bucket? Can you see any evidence of them after the firing?

Sometimes I have little air bubbles that pop on the surface of my freshly glazed piece. I often spend time rubbing them with my finger to smooth them out. But sometimes I just fire them as is. Taking photos before and after will show me whether this step is necessary for that particular glaze.

▢ Glazed test tiles before the firing

This helps me learn the little nuances that did or didn’t affect the fired result.

Testing different dip lengths and deflocculation on a crawl glaze

▢ Which pots were where, in the kiln?

I often take photos as I’m loading or unloading the kiln so I can remember which pots were at the top, middle and bottom, in case there were hot or cool spots in the kiln.

   

Before and after the firing. This top shelf often underfires. I take a pic so I can remember which pieces didn’t quite make it to temp. The glazes on these plates are a lot darker than they would have been if they were fired to temp.

▢ How do the cone packs look?

Sometimes I take photos of the cone packs with the pots that were next to them in the kiln.

These pots were on a shelf that overfired.

Here, I’m documenting that my bisque was slightly overfired. Since these are test tiles, I want to make sure I record that in case it has an effect on test results.

Well, that about sums it up! With your written journal and photo journal combined, you’ll have plenty of information to learn about your glazes and improve your glazing process. When you have before and after photos to compare, you’re more likely to remember your process and repeat results in the future if desired.

Do you keep track of anything I didn’t mention in this article? I’d love to hear about what you like to jot down throughout your glazing/firing process. Please leave me a comment below.

If this post helped or inspired you, please share it with others.

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