Drying
Drying is one of the most important—and most overlooked—steps in pottery. It determines whether your piece survives the kiln (or explodes inside it!) and how smooth, strong, and flawless your final piece looks. Proper drying prevents cracks, warping, and other surface issues, even for air-dry projects. It ensures that underglazes, glazes, and gloss finishes apply cleanly and evenly. This guide covers everything you need to know to dry clay properly, whether you're firing in a kiln or using air-dry finishes.
Why This Matters (Especially for Firing)
If you're having your work fired by someone else, drying isn't optional—it's survival. When clay is heated above 212°F (100°C), any retained water turns into steam. If that steam can't escape through the clay walls, it expands violently—cracking, warping, or completely shattering the piece. Even a pot that looks bone-dry can still hold moisture deep in thick walls, enclosed spaces, or seams. When in doubt, wait longer. A little extra time now prevents heartbreak (and potential damage to another person's kiln) later.
General Drying Timeline
| Type of Piece | Minimum Dry Time |
|---|---|
| Small/thin pieces (pinch pots, coasters) | 7–10 days |
| Standard mugs, small bowls, plates | 10–14 days |
| Large/thick pieces or sculptures | 14–21+ days |
| Enclosed/hollow forms | 21–28+ days |
| After underglaze application | +24–48 hours |
In cold or humid environments, double these times. Patience is your superpower—clay never spoils, but rushing ruins it.
How to Tell It's Fully Dry
Use at least two of these tests before bisque:
Touch test: Bone-dry clay feels room temperature; damp clay feels cool.
Color check: Dry clay is lighter and uniform; dark patches mean moisture remains.
Sound test: Tap gently—dry clay gives a crisp ring, damp clay sounds dull.
Weight check: Dry clay feels noticeably lighter than when freshly made.
24-hour rule: Still unsure? Wait another day (or two). Always safer.
Drying Best Practices
Slow is better than fast: Cover pieces loosely with plastic (cut-up garbage bags are perfect) for the first 2–3 days to slow evaporation. Never seal tightly; moisture must still escape.
Even airflow matters: Place pieces on wooden boards or drywall, not metal or stone (which draw moisture unevenly). Flip once leather-hard to even out top/bottom drying.
Avoid direct sunlight, heaters, or drafts: Uneven drying causes warps and surface cracks. Indirect light or shade is ideal.
Create a "slow-dry zone": Use a loose-lidded cardboard box or plastic tote as a drying chamber to moderate airflow.
Group pieces together: Create a humid microclimate—slower drying, fewer cracks.
Support and balance: Use soft supports (sponges, paper towels) to hold handles or overhangs in shape. For slabs and plates, flip gently halfway through drying for even results.
Mark and track: Date pieces or note "Day 1" when formed. Check progress daily—dark patches or coolness mean it's still releasing moisture.
Special Cases
Thick bases or walls: Add 1 extra week per additional ½" thickness.
Hollow/enclosed forms: Must have a vent hole. Dry 3–4 weeks minimum.
Joined attachments: Score-and-slip seams trap moisture—cover loosely for 48 hours before uncovering.
Underglaze applied on greenware: Wait 24–72 hours before bisque.
Humid/cold environments: Use gentle air movement (fan at distance). Never direct heat.
Common Drying Mistakes
Rushing to fire because "it looks dry"
Surface may be dry while inside is damp. Perform multiple dryness tests and respect minimum drying times.
Using a heater or fan directly
Causes fast surface shrinkage and cracks. Air-dry naturally, ventilate gently.
Drying in sunlight or window
Uneven drying causes stress cracks. Use shaded, stable environment.
Keeping sealed in plastic too long
Prevents evaporation entirely. Vent plastic daily or remove gradually.
Ignoring thick spots and joins
These hold moisture longest. Inspect and extend drying time.
Firing soon after underglazing
Adds hidden moisture. Wait 24–48 hours minimum.
Studio Secrets
Garbage bags = perfect slow-dry covers. Cheap, flexible, and easy to vent.
Cardboard boxes double as dust guards. Keeps your drying zone clean and even.
Paper test trick: Lay a paper towel under the piece. If it darkens overnight, moisture is still escaping.
Humidity "buddy system": Dry several pieces together to stabilize moisture exchange.
Handle with care: Even bone-dry clay chips easily—lift from the base, not the rim.
Document everything: Take photos before firing—helpful if pieces break during transport or firing.
Quick Drying Checklist (For Kiln Drop-Off)
Piece dried at least the minimum time for type
Feels room temperature, not cool
No dark or glossy damp patches
Tap test gives a clear ring
Base, handles, joins double-checked for moisture
Underglaze (if any) dried 24–72 hours before firing
Photographed and labelled for firing
Packed securely for transport
When unsure — waited longer
The Bottom Line