Uni POSCA Paint Markers, Surface by Surface

POSCA is water-based pigment paint in a pump-valve barrel, made by Mitsubishi Pencil under the uni name. That chemistry is why it covers paper, glass, wood, metal, plastic, stone and cardboard without a primer, and why it needs pressing and shaking before the first stroke. It is also why it is filed here under paint markers and turns up again under acrylic.

POSCA is water-based pigment paint delivered through a pump valve. Every practical thing about the pen follows from those two facts, including the surfaces it covers and the one habit it demands before the first stroke. The parent page explains how paint markers are matched to a job across all 260 of them; this page is about the one range that 200 searches a month name directly, at keyword difficulty 5.

Water-based pigment, and what it buys you

Solvent inks work by soaking in. Pigment paint works by sitting on top. That is why the paint row in the matrix is one of the broadest works rows in the grid: paper at 250 searches, chalkboard at 390, glass at 3,870, wood at 270, metal at 990, plastic at 610, stone at 290 and cardboard at 10. None of those cells needs a primer, and none of them cares whether the surface is porous, because the pigment never had to bond into anything.

Two cells are conditional rather than clean. Ceramic at 120 searches is conditional because the mark is not dishwasher safe unless the range is bake-set. Fabric at 3,160 is conditional because a pigment film on a woven fibre stiffens the weave and is only semi wash-fast. Car window is conditional at 2,350 with a firm warning attached: water-based only, on glass only, never on paint. Skin is a flat fail at 1,000 searches a month, and that is 1,000 people a month asking a question whose answer is no.

Because POSCA is pigment with a binder, it also sits in this site's acrylic list, and both labels are correct. The naming question has its own page at are POSCA markers acrylic, which 330 searches a month reach for.

The valve, and why "press down markers" is a real search

Twenty searches a month in this cluster are for "press down markers", which is a description rather than a brand. POSCA nibs are plungers. Pigment is heavy and would set in a felt nib left open, so the barrel keeps it sealed until you press the tip against a hard surface and let paint through. Shake first, press two or three times on scrap paper, then work. Skipping that step is the single most common way a new POSCA appears to be faulty.

It is also the source of the type's most-reported failure. Ink flow draws 1,196 buyer reports across 19 paint marker products with 585 negative, at 49%, and the negative half divides between pens that give nothing and pens that give everything at once.

"the pens vigorously and pumped each one for several minutes and no ink came out. They all appear to be dried out or empty" posca PC-1MR Water-Based Paint Markers, Extra Fine Tip

"the cap is on, because if you shake it while the cap is off paint goes everywhere" Uni Posca Paint Marker Pen, Extra Fine Point, Set of 7

The counterweight is in the same corpus and it is about coverage rather than flow: "Will write smoothly on ANYTHING. Rough painted wood full of glitter? YUP. Rough galvanized aluminum? YUP. Glass? Too easy", written about the PC-3M reversible fine tip.

Price, rating and where POSCA sits in the field

Across the 174 POSCA products in this catalogue, the median price is $15.83 and the median rating is 4.7. The site-wide medians are $13.99 and 4.6. POSCA is therefore more expensive than the field and rated slightly above it, which is an unusually clean position for a brand of this size — most of the 908 brands here beat the field on one of those two numbers and lose on the other.

Within the type, paint markers as a whole have a median price of $11.89 across 260 products, so POSCA sits well above its own category rather than above the site in general. The ranked table below is filtered to products rated 4.3 or better with at least 1,500 ratings and a live price.

Tip codes are the other half of the buying decision, and they are consistent across the range: PC-1M is extra fine, PC-3M fine, PC-5M medium and reversible, PC-8K broad chisel. The medium reversible tips are the ones that survive rough surfaces longest, because a bullet nib pressed sideways on stone or timber wears fastest at the point.

The demand behind this page

Four keywords carry 280 searches a month here. "Uni posca paint markers" is the largest at 200 and the fastest-moving, up 104.4% year on year at keyword difficulty 5, the only non-zero difficulty in the group. "Where to buy paint markers" adds 50, "press down markers" 20 and "posca markers box" 10.

That growth figure is worth reading against the brand's size. POSCA carries 73,310 searches a month across its own brand cluster on this site, so this page is a small door into a large room. What sends people through this particular door is the full product name — uni, POSCA, paint, markers — which is the phrasing of somebody checking a specific pen before buying rather than browsing a category.

POSCA questions, answered from the data