Antique ceramics —vases, plates or porcelain figures— are some of the most beautiful pieces you can find in an antiques shop, but also some of the most delicate. A glaze fired decades or centuries ago doesn't behave like modern tableware: it may have invisible cracks, loosely fixed painted decoration, or old repairs hidden under a layer of paint. Before cleaning or storing an antique ceramic piece, it's worth knowing a few basic rules that make the difference between preserving it well and accidentally damaging it.
First, examine the piece
The first step isn't cleaning, but taking a calm look: checking for cracks, chips, flaking decoration or previous repairs. If there's any structural damage, conservation specialists recommend consulting an expert before washing it, because a fragile piece can break further during an apparently harmless wash (Museum of Royal Worcester, n.d.). This inspection is also useful for spotting crazing: the fine network of cracks that appears in the glaze over the years and which can let water and dirt into the body of the piece.
How to clean it without damaging it
For dust, a cotton cloth or a soft brush is usually enough. For more stubborn dirt, the usual recommendation is lukewarm water with very little neutral detergent, applied with a damp cotton swab rolled gently over the surface, never scrubbed hard; rinse thoroughly and dry with a lint-free cloth (Museum of Royal Worcester, n.d.). Some restorers clean more ingrained dirt by wiping with alcohol, but always testing beforehand on an inconspicuous area, since it can alter the original colour; if there's a risk of discolouration, it's safer to use neutral soap and water, even if it takes longer to dry (Consumer Eroski, n.d.).
What you should never do
The dishwasher is completely out of the question for valuable pieces: heat and harsh detergents can crack the glaze or wipe away hand-painted decoration. Bleach and other strong products should never be used either. If the piece has crazing, it's better not to submerge it fully in water, since water can get trapped in the cracks. And a damp swab should never be run directly over already-repaired areas or decoration that looks loose (Museum of Royal Worcester, n.d.).
Small repairs
For fine cracks, some amateur restorers use white cement mixed with colourants until it matches the original tone. For broken pieces, epoxy putty is common: it's shaped by hand, moulded to the piece and hardens with strong adhesion; any excess is then smoothed down with a fine file or sandpaper. Before painting or varnishing, it's worth testing on a similar surface to check the tone matches well (Consumer Eroski, n.d.). For pieces of significant value, the safest option is to leave the repair to a professional.
Where and how to store it
Inside a display cabinet, a chamois leather base under the pieces absorbs vibrations and keeps them from knocking against each other. If a piece needs wrapping, acid-free tissue paper and bubble wrap are the safest materials —never tape applied directly to the piece— and for transport a sturdy box with plenty of padding is best, away from humidity and sudden temperature changes (Museum of Royal Worcester, n.d.).
Looking after an antique ceramic piece doesn't require special products or being a professional restorer: patience, lukewarm water, a soft cloth and avoiding everyday dishwashing shortcuts are enough. If you'd like to discover ceramic and porcelain pieces with their own history, take a look at Ca l'Antic's catalogue.
References
Consumer Eroski. (n.d.). Restaurar piezas antiguas de cerámica. Consumer.es. https://www.consumer.es/?p=14290
Museum of Royal Worcester. (n.d.). Care of ceramics. https://www.museumofroyalworcester.org/discover-learn/china-care/care-of-ceramics/