Glazing (Firing) Guide

Glazing & firing is the traditional ceramic finishing method that transforms fragile clay into durable, food-safe, dishwasher-proof pottery with a permanent glass-like surface. A fired glaze bonds to the clay at high temperature, producing a professional finish that lasts decades. It requires access to a kiln and patience, but it delivers functional pieces you can actually use every day.

If you don't have kiln access or want quick results, see our Gloss Guide — it's faster but not food-safe or as durable.

Difficulty: Beginner–Intermediate

Time: Variable

Quick Facts

Timeline: 10–14+ days drying (longer for thick pieces) → Bisque turnaround often 1–2 weeks → Glaze firing 1–2 weeks (depends on kiln schedule)
Firing Temp: Bisque typically cone 04–06; Glaze (kit glaze) cone 06 (low-fire)
Equipment: Access to kiln Find-a-Kiln
Safety: Read the Drying Guide first — retained moisture = explosions

What You Need

The 'Glaze' jar (clear low-fire glaze)

Thick natural-bristle brush

Wax resist (optional)

Damp sponge & clean water

Kiln access or friendly kiln operator

Firing instructions for kiln operator

Step-by-Step

Ensure Completely Dry

Wait to dry fully: After forming or applying underglaze to greenware, wait at least 10 days for typical pieces — thicker items often need several weeks. Follow the Drying Guide (kit portal). Damp clay will have a slightly cold feel to the touch.
Bisque Firing

What is bisque? Bisque is the first firing that transforms fragile greenware into a porous but durable ceramic you can handle and glaze. It's permanent — you can't undo bisque.

Bisque temp: Bisque to cone 04.

Timeline & turnaround: Bisque firing cycles usually take 6–10 hours to heat plus cooldown. Many community kilns batch weekly — expect 1–2 weeks turnaround from drop-off to pickup.

Shrinkage & colour shift: Clay shrinks ~10% during drying and firing, and the colour will shift from greyish to a creamier beige tone.
Surface Prep After Bisque

Bisque is dusty and porous — wipe with a slightly damp sponge to remove dust before glazing. If you underglazed on bisque: wait 24 hours to ensure the underglaze is fully dry before glazing. Take a photo of your piece — it helps your kiln operator locate and return your work, and gives you a memento if tragedy strikes!
Glaze Prep & Application

Stir the glaze: Pigments settle — stir well before each use (use a clean brush).

Coating strategy for evenness: Apply 2–3 even coats. Alternating between vertical and horizontal strokes helps reduce streaks.

Thickness: Each coat should feel like heavy cream — you should see brush strokes when wet, but after 2–3 coats the bisque should no longer show through. Wet glaze looks milky or opaque but fires clear.

Interior glazing: For tight-neck functional pieces, pour slightly watered-down glaze (approx. 1–2 tsp per 50 mL) inside, swirl to coat, and pour the excess back into a separate jar (do not return contaminated thinned glaze to your main jar).

Hold by the foot: When glazing exteriors, hold the piece by the unglazed bottom. If you must touch a glazed area, dab glaze back over the area touched.

Fingernail test: Run your fingernail along the foot rim — if you feel any glaze, wipe it off with a damp sponge. Even a small bit of glaze on the foot can fuse to the kiln shelf.
Pre-Fire Checks

Dry time: Let glaze dry fully — about 24 hours.

Final clean: Triple-check the base and foot; use a damp sponge to remove any stray glaze.

Photo & packaging for transport: Photograph your finished, dry piece. Pack carefully for transport to the kiln.

Glaze fire temp: Fire to cone 06.

Studio Secrets

→ Wet sponge = your best friend: Wipe glaze mistakes while wet — easier than panicking later.

→ Glaze inside first: Pour and coat interiors before exteriors — keeps the foot dry.

→ Buddy test tile: Fire a small test tile with every batch to preview how the glaze and clay behave.

→ Thin is king: Multiple thin coats beat one thick coat every time — fewer runs, holes, and surprises.

→ Kiln karma: Clean shelf drips before loading — old dried glaze can stick to new work.

→ Photo proof: Take photos before drop-off — great for record-keeping and resolving damage issues.

→ Patience pays: Rushing drying or firing causes most beginner failures. Wait longer if unsure.

→ Underglaze shifts: Reds and yellows often shift under clear glaze — test combinations first.

Helpful Fixes

Cracks or explosions in bisque

Cause: Retained moisture or trapped air.
Fix/Prevention: Dry longer, hollow large pieces, add vents, compress seams. If it happens, clear shards carefully and learn where moisture or air was trapped.

Glaze running or dripping during firing

Cause: Too thick or too close to the base.
Fix: Cannot fix after firing. Next time: thinner coats, wider unglazed margin (2–5 mm), use wax resist. If fused to the shelf, your kiln tech may need to grind it off.

Crazing (fine crackling in the glaze)

Cause: Glaze/clay fit mismatch or thermal shock.
Fix: Cosmetic; usually still food-safe. Prevent by matching glaze to clay or adjusting firing ramp. Cannot reliably fix after firing.

Pinholes or bubbles

Cause: Gases escaping (organic matter or trapped air) or thick glaze.
Fix: Apply thinner coats, improve clay prep, consider an additional bisque or slower firing. You can sand, re-glaze, and re-fire if possible.

Cloudy or white glaze after firing

Cause: Underfired or glaze applied too thickly.
Fix: Re-fire to the recommended temperature or use thinner coats. Consult your kiln operator.

Stilts stuck to bottom / stilt marks

Cause: Stilts leave marks — normal.
Fix: File or sand lightly with a diamond pad; small marks are expected.

Piece broke or cracked after firing or in transport

Cause: Moisture, thermal shock, or rough handling.
Fix: Prevent with extra drying time, careful packaging, and gentle transport. Learn and retry — it happens to everyone.

Colours look different than expected

Cause: Underglaze + clear glaze interaction or firing atmosphere.
Fix: Test on tiles, keep notes, tweak colours or clear glaze, and embrace some beautiful surprises.

Quick Checklist

Piece is fully dried

Bisque fired to cone 04–06

Wiped clean with damp sponge

Glaze jar stirred 2–3 minutes

Test tile glazed with batch

Interior glazed before exterior

2–3 thin, even coats applied

Base & foot clean (fingernail test)

Glaze fully dry (≈24 hours)

Photo taken & piece labelled

Kiln operator confirmed schedule

Prepared for 2–4 week turnaround

You've got this. Thousands of beginners fire their first pieces successfully every week — and yes, even master potters lose work in the kiln sometimes. Each failure is a lesson in clay behaviour and kiln science. Be patient, document your experiments (photos + notes), and talk with your kiln operator — they're your best resource.