The key word is Function! How to keep your handmade ceramics going strong
My cupboards are full of handmade ceramics - not only mine but those of other artists and makers I admire, or just random pieces I found somewhere and loved. There's a charm to handmade objects - they are never "perfect," never exactly the same, even when they are very close. I love seeing the tell-tale signs of the handmade, perhaps a trace of the spinning of the pottery wheel, little marks left by fingers or tongs in the glaze that remain even after firing, brushstrokes, indentations and alterations in the form. All this leaves an impression of the maker behind.
Pottery is found in archaeological digs routinely, and one can still admire the makers' works centuries later. This is even true of some of the more delicate, low-fired work. High-fired (at temperatures exceeding 1200ºC) work is usually more durable, but you can enjoy your handmade ceramics for a very long time by treating them well.
Hand-washing versus Dishwasher, and General Cleaning Tips
Although my functional ceramics are dishwasher safe, for the very best results, it's best to wash them by hand or on a lower temperature setting. If you can arrange them in the dishwasher so that they are not resting on each other, they are less likely to develop small chips. I'll be honest, I don't bother, and mostly that's fine. I don't mind things slowly developing tiny signs of wear. Most of the "feet" on things I use have tiny chips from stacking and clacking together. It doesn't affect their functionality. I have a few very precious things that I always wash by hand, but mostly I don't.
A couple of note-worthy things:
Raku pieces should never go in the dishwasher, and never be used with household vinegar. It will remove the metallic effects caused by the high-temperature application of organic material. It will still be functional and beautiful, but if the lustre was what attracted you to the piece, it will be lost.
On the note of lustre, if the piece has a metallic element, like a gold rim for example, you should wash it by hand as well.
If there are places on the piece that will collect lots of water in the dishwasher, like the foot of a goblet, you would be better off hand-washing it. The hot water inside can in rare circumstances weaken a potentially weak bond and cause a split. I once did a lovely series of goblets where a different type of clay formed the base, and the bond was not perfect. The ones that went in the dishwasher split in two. It wasn't the end of the world - I simply glued them back together with a strong epoxy and continued to use them - but it wasn't ideal. This is indeed a fault in the making, but I might never have learned about it had I been more careful with them in the first place.
Finally, never use harsh scouring pads or chemicals on handmade ceramics. They could damage the glaze. Instead, allow to soak in normal soapy water then if necessary scrub with a silicon brush or soft cloth.
Tea and coffee stains can be soaked away with a very light chlorine (bleach) solution, 2 tablespoons (30ml) per liter or quart of water, for 1 or 2 minutes, immediately rinsed then washed with normal soapy water.
In time, your bowls and cups especially may show black marks from spoons in them. You can remove those with good quality, non-abrasive metal cleaner. Those and small scratches can also be removed in a very low-temperature firing (low for ceramics, that is), but there's always a risk involved in re-firing pottery. The kiln gods do not always smile.
Microwave and Oven Use
Obviously, if the ware was fired already to temperatures over 1000ºC, it can handle your microwave or oven. However, what most handmade pottery can't handle is the abrupt temperature shift or uneven warming of substances in it. I am not currently making oven ware, although I would like to. Clay for ovenware usually has lots of "grog" in it - broken tiny bits of ceramics - to help strengthen it for this purpose. Often this is hand-built, rather than wheel-thrown, because working very groggy clay on the pottery wheel can really tear up your hands. That doesn't always stop us potters from doing it, but ... if you keep an eye out for how ovenware is shaped, you'll see this is mostly true.
If you do choose to use your handmade pottery in the oven, or even in the microwave, do not simply set it on a cold hard surface afterwards. It would be best to use a wire rack or even a cork pot rest. It's still a risk that the bottom will crack from the temperature shock if the heat was high enough in the oven. And in general, avoid larger, flatter ceramics in a hot oven. They are the most likely to crack.
The only real downside to the microwave is that I find the heat goes too much through the clay to be comfortable to hold afterwards. But then, I haven't owned a microwave in over 20 years, so... could be I'm just biased against microwaves.
Basically, avoid sudden temperature changes. If you are pouring hot coffee into a cold mug, it may help prevent any cracking to put a spoon into it first. Don't worry if there is crackling in the glaze. It's called crazing, and while some potters will tell you it's problematic, it's mostly a cosmetic issue. Discussion of crazing is a whole separate topic. Perhaps I'll write about that another time.
I hope this has little article has helped you understand better how to care for your handmade pottery. I'm personally not always so careful with my own, but then, I made them and I can make new ones if I break them. If you break yours, it's a different story.