How to Use POSCA

Know your marker

A POSCA isn't a felt pen. Inside the barrel is water-based pigment paint and a mixing ball; the tip sits on a valve that only opens when you press it down. That's why a new pen writes nothing until you prime it — and why shaking matters.

The parts of a POSCA marker.

Pick your tip size

Ten tips, one paint. The code on the barrel tells you the line it draws — everything else about the pen is the same. Pick the line you want and the code follows.

Which tip for which surface?

• Paper, card, sketchbooks — 1MR, 1M, 3M, 5M.
• Rocks, wood, ceramics — 3M and 5M for detail, 7M or 8K for base coats.
• Fabric & sneakers — 3M and 5M, then heat-set.
• Glass, windows, café boards — 5M, 8K, 17K.
• Murals and large-scale — 7M, 8K, 17K, MOP'R.

Starting a new pen

1. Shake with the cap on until you hear the ball rattle — around 20 shakes. This mixes the pigment back through the paint.
2. Press the tip down on scrap paper. Straight down, hold a second, lift. Repeat.
3. Wait for the colour. Most pens take 5–10 presses. White, the metallics and the broad tips take longer because there's more tip to fill.
4. Test a line before you touch the real thing.

Priming, testing, drying and fixing.

Preparing the surface & making it stay

Every surface falls into one of two camps, and which camp it's in decides everything.

Porous surfaces — it soaks in and stays

Paper, card, canvas, raw wood, stone and pebbles, terracotta, unglazed ceramic, fabric. Clean and dry is all the prep you need; sand timber smooth and dust it off. Once dry the paint is there for good — no sealing required unless the piece lives outdoors or gets handled hard.

Non-porous surfaces — it sits on top

Glass, glazed ceramic, smooth metal, PVC-type plastic, laminate. Wipe with methylated spirits first so there's no grease. The paint will wipe off with a damp cloth until you fix it — brilliant for window art you change each season, a problem for a mug you want to keep.

Surface preparation and fixation, surface by surface.

Three ways to fix it permanently

• Varnish — let it dry 24 hours, then spray clear acrylic varnish in several light passes from about 30cm. One heavy wet coat can reactivate the paint and smear it. Test on a scrap first.
• Bake (glass and ceramic) — dry fully, place in a cold oven, bring up to around 160°C, hold about 45 minutes, then let it cool in the oven so it doesn't crack. Decorate the outside only and stay below the rim. Hand wash afterwards.
• Iron (fabric) — dry fully, turn inside out, put a cloth between iron and fabric, press with a dry iron, no steam, for a couple of minutes. Then wash inside out, cold, and skip the dryer.

Care & maintenance

POSCA pens last for years if you look after the tip — which is where almost every problem starts.

• Dry tip? Pull it out with tweezers, soak in warm water until the dried paint releases, squeeze out, dry, refit, shake and re-prime.
• Dirty tip? It has picked up colour from paint that wasn't dry. Press on scrap until its own colour returns, or rinse the tip under warm water.
• Worn tip? Replace it — a new nib costs a fraction of a new pen.
• Storage: cap on firmly, out of heat and sun. Brush tips flat, everything else upright.

Use, care and maintenance.

Techniques worth learning

• Layering. POSCA is opaque, so light goes over dark. Let each layer dry completely or the tip lifts the colour underneath.
• Blending. Work two colours together while wet, or soften an edge with a damp brush — water reactivates POSCA right up until it dries.
• Water effects. A wet brush turns fresh POSCA into a wash. Great for skies and backgrounds.
• Mixing. Put two colours on a palette or a tile and mix them like paint before you apply.
• Drips and splashes. The MOP'R (PCM-22) and the broad tips hold enough paint to drip on purpose.
• Blowing. A loaded tip plus a straw gives you the classic splatter burst.

Creative techniques.

Safety and sensible use

POSCA paint is water-based, non-toxic and odourless, which is why it's a classroom staple — no solvent fumes. A few rules still apply:

• Fine for children with normal supervision. Caps are small, so keep them away from toddlers.
• Not approved for skin, face or cosmetic use. Use proper body paint for that.
• Decorate mugs and glasses on the outside only, below the rim, and hand wash.
• Only mark property you own or have permission to mark.
• Cover the table. POSCA is designed to stay put — see the FAQ on getting it off things if it doesn't go to plan.

Safety and other uses.