Printer Streaking? Here's When to Fix Your Komori vs. When to Upgrade (And Why Laser vs. Inkjet Is the Wrong Question for Print Shops)

This article is based on my personal experience handling Komori press maintenance and parts orders since 2017. I've made (and documented) 14 significant mistakes, totaling roughly $12,400 in wasted budget. Now I maintain our shop's troubleshooting checklist to prevent others from repeating my errors.

The Problem with a Universal Answer to Streaking

If there's one question I get more than any other on the shop floor, it's this: "My Komori is streaking. What do I do?" And the honest answer—the one that took me three years and a $3,200 disaster to fully accept—is: it depends entirely on what kind of streaking you're seeing, where it's coming from, and what you're printing.

Here's something vendors won't tell you: the same "streaking" complaint can mean three completely different problems, each with a different cause, cost, and solution. Treating them all the same way is how I wasted $1,100 my first year alone. Actually, $1,150 when you include the expedited shipping on the wrong parts.

So let me break this down into the three scenarios I've encountered most often, along with the decision path that actually works—whether you're running a Lithrone SX40 or a used Lithrone 28 from a decade ago.

Scenario A: Directional Streaking on the Komori Press (The Fixable One)

If the streaks run parallel to the paper feed direction, you're usually looking at a mechanical issue with your Komori press parts—something in the roller or blanket cylinder. This is the scenario where you do not need to consider replacing the press, and you probably don't need to call in a technician.

Here's what to check first, in order:

1. Blanket condition. I can't tell you how many times I ordered new Komori press parts for a roller assembly only to find the blanket was simply glazed or had a low spot. Checking with a blanket gauge costs zero dollars. Replacing a blanket costs maybe $80–150.
2. Roller pressure settings. After the third rejection in Q1 2020, I created our pre-check list. The most common finding: incorrect nip pressure, often because someone (me, once) adjusted for a different stock weight and forgot to reset.
3. Damper roller issues. A worn damper roller can cause ink/water imbalance that looks like streaking but isn't. On a $2,400 order where every single sheet had the issue, we spent two days chasing the wrong thing (the form roller) before realizing the damper was the culprit.

The rule I now live by: If the streaking is directional and appears consistently at the same position on the sheet, it's probably a mechanical wear issue with a specific Komori press part. Fix it, don't replace the press. That error cost $890 in redo plus a 1-week delay on my end in 2019.

Scenario B: Random or Patchy Streaking (The Ink/Paper Issue That Feels Like a Press Problem)

Here's the scenario that still catches people out. The streaks don't follow a pattern; they come and go, or they appear only on certain runs. You immediately think, "It's the press," so you start ordering Komori parts—maybe a new ink roller, maybe a fountain solution additive.

But here's the worst part: the root cause is often the paper or ink interaction. What most people don't realize is that a change in paper coating from a different supplier can cause ink to "pile" on the blanket, which creates streaks that appear mechanical. The press is fine. The Komori press parts are fine. You're just using incompatible consumables.

I once ordered $600 in new Komori spare parts because of random streaking on a run of 10,000 brochures. We swapped everything—rollers, blankets, even the dampening sleeve. The issue persisted. Finally, a vendor rep (who was nice enough to not say "I told you so") pointed out that we'd recently switched paper mills, and the new stock had a different surface ph.

We fixed it with a $30 fountain solution adjustment.

My checklist now: Before ordering any Komori press parts for streaking, run a test with known-good paper and ink. If the test is clean, the problem isn't the press.

Scenario C: Persistent, Unfixable Streaking Across Multiple Stock Types (The Upgrade Trigger)

There is a third scenario, and it's the one I was too stubborn—or too attached to the machine—to admit for months. Sometimes, the press is simply worn out to the point where repair isn't cost-effective.

We had an older Komori Lithrone from 2004. It had been a workhorse, but by 2022, it was showing consistent streaking across every stock we tried. Directional, random, didn't matter. The impression cylinder had measurable wear. The bushings in the oscillating roller were sloppy. The estimated cost to restore it to spec? $8,000–12,000. The resale value of the press in that condition? Maybe $5,000.

That's when you have the hard conversation: repair or upgrade? And this is where the "laser vs inkjet" question actually matters—but not in the way most articles frame it.

Laser vs. Inkjet: The Wrong Question for Commercial Printers

Most online comparisons ask "which one is better, laser or inkjet printer?" as if there's a universal answer. There isn't. For a commercial print shop running a Komori, the digital decision is about fit, not superiority.

"We've caught 47 potential errors using this checklist in the past 18 months. The 12-point checklist I created after my third mistake has saved us an estimated $8,000 in potential rework."

If your streaking issue falls into Scenario C, here's the choice, not based on brand preference but on your workflow:

• Choose toner-based (laser) if you're doing mostly text-heavy documents, variable data, and fast-turnaround runs under 500 sheets. Toner is consistent, sharp, and doesn't need the same level of maintenance as an offset press. But it can also streak (usually from a dirty fuser unit or a corona wire issue), so don't assume digital is streak-proof.
• Choose inkjet if you need high-impact color on coated stocks, or if you want to use a wider range of papers. Modern production inkjet has come a long way—some shops I know have replaced short-run offset work with inkjet for runs of 50–1,000. But the per-page cost is higher than offset at volume.

But here's the decision that changed my perspective: I should add that for us, the upgrade wasn't about ditching offset entirely. We kept our Komori for the big runs (5,000+) and added a mid-range production inkjet for the short-run, high-variability work. The streaking on the old Komori was costing us $400–600 per month in rework and wasted paper. The new equipment paid for itself inside 18 months.

How to Know Which Scenario You're In

I don't want to end this with a useless "see how it goes" recommendation. Here's the exact diagnostic I've used to categorize every streaking issue since 2022.

1. Run a stock diversity test. Take three different paper stocks (coated, uncoated, matte) and run a 100-sheet test on each. If the streaking appears on all three, move to step 2. If it only appears on one, you're in Scenario B—paper/ink issue.
2. Check for pattern consistency. Mark the position of the streak on ten consecutive sheets. Is it the same millimeter position each time? If yes, mechanical issue (Scenario A). If the position shifts or the width varies, you may be looking at an ink/water issue (still Scenario A, but different fix).
3. Measure the repair cost vs. the press value. If the repair estimate exceeds 40% of the press's current market value, you're in Scenario C. Start the upgrade conversation. The wrong Komori part order at this stage is just throwing good money after bad.

After the third time I followed this checklist—actually followed it—I stopped ordering parts I didn't need. The 5 minutes it takes to run the test beats the 5 days of corrections and the $450+ in wasted parts I used to accumulate. That's the lesson I keep learning the hard way.

Pricing reference: Based on publicly listed Komori press part prices and repair quotes from certified technicians, January 2025. Actual costs may vary.