The color has faded – Printer Cleaning Issues Part 18 ARTJET 2026

• When ink enters the Damper from the main ink bottle via the ink tube, it passes through the print head, flows to the captop, moves through the motor pump, and finally drains into the waste ink bottle.
• This article covers The Color Has Faded in the full ink supply problem series.
• This follows Part 1 Captop Lower Tube, Part 2 How to Replace the Captop, Part 3 Damper, Part 4 Pump Motor and Yellow Tube, Part 5 Captop and Head Position, Part 6 Aligning the Captop and Head Position, Part 7 When the Capping Station Level Is Not Correct, Part 8 Captop Surface Drying, Part 9 Degraded Ink Inside the Captop, Part 10 Time for Ink to Fill the Damper, Part 11 Ink Tube Burst, Part 12 How to Replace a Motor Pump Tube, Part 13 Why White Cleaning Doesn’t Work Well, Part 14 Why It’s Important to Replace the Yellow Tube and Captop, Part 15 Head Protection Plate Crumpled, Part 16 Head Protection Plate Cracked, and Part 17 When a Specific Color Drops Out During Printing.

This is a question first-time UV printer users inevitably ask.

When someone says the color has faded, we first need to check whether a specific ink is actually missing, or whether it’s a different symptom entirely. At this point we usually ask for a nozzle test pattern or a photo of the printed image.

After seeing this issue reported a few times, here’s the fix we now give:

• Pump White ink only, and stop 15 seconds after ink starts flowing into the waste tank,
• then clean and run a nozzle test.
• If the White nozzle still isn’t right, repeat cleaning once or twice and test again.
• Once the nozzle test pattern looks reasonably good, print a test image.
• If that’s fine, go ahead with the actual job.

This one caught us off guard the first time it was reported.

• Looking at the photo above, the left side looks dull and the right side looks bright.
• Looking only at the Color makes it easy to mistake this for a Color-specific problem.
• But if you look closely at the White instead of just the Color,
• the White on the left is dark, and the White on the right is bright.

• Just like printing Color on a dark background makes the whole thing look dark and unsaturated,
• think of it as printing on paper with a darker undertone instead of pure white paper — that’s what a diluted White looks like.
• “The colors look faded” and “the right color starts showing up partway through the print” — both come from the same cause: diluted White density.

CMYK, Lc, Lm — the pigment in Color ink is relatively small in amount and particle size, so it doesn’t settle to the bottom.

• To render color properly, just the right amount of pigment needs to be added.
• Too much makes it dark and muddy; too little fails to render the color properly.
• In other words, there’s no need to load Color ink with heavy pigment.
• Because Color ink doesn’t carry much pigment, it stays evenly dispersed compared to White pigment and doesn’t settle.

White ink, on the other hand, is far more demanding when it comes to the pigment that renders white.

• First, achieving true white requires a White pigment that actually renders as white (other inks tend to carry a slight yellow undertone).
• Second, White printing needs to create proper opacity, even over transparent or colored materials.
• For these reasons, White ink’s pigment particles are larger than Color’s.
• It also carries as much pigment as stability allows — up to the maximum safe amount.
• So compared to Color ink, White ink has both larger and more abundant pigment.
• Because of this, if White ink isn’t stirred regularly, the heavier pigment settles to the bottom, leaving dense White below and thin, pigment-poor White above.

In printer terms:

• Most main ink tanks have a built-in stirring device, so White ink stays well mixed inside the tank itself.
• But the roughly 2.5-meter ink tube running from the main tank to the Damper has no stirrer or circulation device at all.
• With daily use, ink keeps moving through the tube, so heavy pigment has no chance to settle.
• But after 2–3 days without use, the heavy pigment in the White ink sitting in the tube settles toward the bottom.
• As White pigment collects at the bottom, the White at the bottom of the tube becomes dense, while the White near the top becomes thin.
• That thinner White at the top is lighter and flows more easily, so convection pressure carries it into the Damper first — which is why thin White comes out initially.
• During a nozzle test, this thin White still prints fine since it’s technically intact, so printing proceeds.
• When that thin White gets printed as the base layer and Color goes on top, the Color ends up looking dull because of the weak White underneath.

Ink load, or pumping, is the process of forcibly draining out ink.

• Running an ink load drains the separated ink sitting in the ink tube into the waste ink tank,
• and refills the ink tube and Damper with fresh ink from the ink bottle.
• Printing in this state produces White at a higher, more consistent density.
• Note that the White ink inside the Damper can also separate into layers over time, so rather than running a longer White clean in some cases,
• a short ink load followed by cleaning can restore the White nozzle condition more quickly.