5 Checklist Steps to Avoid Costly Offset Printing Errors (Komori Press Focus)

I’ve been handling technical print orders for Komori presses for about 8 years now. I’ve personally made (and documented) what feels like every mistake in the book—maybe 15 significant ones, totaling roughly $18,000 in wasted budget. The worst was a $3,200 order where every single sheet had the wrong color profile because I’d trusted a file preview. That one hurt.

This checklist is for anyone who runs a Komori Lithrone or similar offset press, especially if you’re taking on smaller, diverse jobs where margins are tight and there’s no room for reprints. It’s a practical, step-by-step guide to avoid the pitfalls I’ve already fallen into.

Here are the 5 steps I follow on every job now. Miss one, and you might be looking at a $500 redo.

Step 1: Pre-Flight Your Digital Files (Never Trust the PDF Preview)

This is where I made my first big mistake back in 2017. I assumed the PDF proof from the client looked fine. It did—on my screen. The result came back with all text at 72 DPI, blurry, and unreadable. 500 flyers, $450, straight to the trash.

Do this: Manually check every linked image’s resolution. Don’t rely on the PDF’s ‘pre-flight’ report alone. Set your pre-flight settings to flag anything below 300 DPI at final size. For a Komori press, you need that sharpness.

Check this: Are all fonts embedded? Are there any missing fonts? This will cause a RIP error mid-run, which costs time and sometimes plates.

(Should mention: I also check for spot colors that haven’t been properly defined. A client’s ‘brand blue’ that’s supposed to be CMYK but shows up as Pantone? That’s a setup fee and a reprint waiting to happen.)

Step 2: Match the Paper Stock to the Job (Not Just the Budget)

Paper weight and finish are often treated as an afterthought. In my experience, that’s a mistake. I once ordered 1,000 business cards on 100lb cover stock when the design had heavy solids. The ink coverage was fine, but the card felt flimsy. The client was unhappy. The reprint cost $120, plus a week delay.

Here’s a rough guide I use for Komori jobs:

• For flyers with heavy ink coverage: 100lb text gloss or matte. Anything lighter and you risk show-through.
• For brochures with multiple folds: 80lb text or higher. Lighter paper will crack at the fold.
• For business cards: 14pt (about 100lb cover) is the sweet spot. Lighter feels cheap; heavier might jam the feeder on some older presses.

Check this: The paper grain direction. If you’re folding, the grain should run parallel to the fold. If it’s perpendicular, the paper will crack. That’s a hard lesson I learned when I made 200 brochure covers that all had ugly white lines down the middle.

Reference: Industry standard paper weight equivalents. 100lb cover is roughly 270 gsm. Verify with your supplier, as naming conventions vary.

Step 3: Confirm Special Finishing Requirements (Embossing, Die-Cutting, Foiling)

This is the step where small jobs go sideways. A client might order 500 pocket folders with a simple die-cut for a business card slot. If you don’t confirm the die-line and its tolerances, you might end up with a slot that’s too tight or too loose.

The worst-case scenario I saw: A $2,000 order of custom folders with foil stamping. The foil die had a hairline crack, and we didn’t catch it until 200 pieces had a broken ‘e’ in the logo. That mistake cost $890 in redo plus a 1-week delay.

Do this: Create a final, signed proof that includes the die-line and foil placement. For offset presses like the Komori, the plate registration for these processes is critical.

Check this: The feeder and delivery sections of your press. Can it handle the thickness of the paper plus the foil or embossed areas? Some older Komori models have a maximum thickness limit. Check the spec sheet before you start.

Calculated the worst case for skipping this step: complete redo at $2,000. Best case: it works fine. The expected value says go through the checklist, but the downside feels catastrophic. That’s why I don’t skip it anymore.

Step 4: Calibrate Your Press for the Specific Ink and Paper Combination

The same ink on different paper stocks will look different. This is obvious to experienced operators, but I’ve seen it cause problems. For example, printing a vibrant blue on a matte vs. gloss stock can change the perceived saturation by 10-15%.

Do this: Run a short test strip (maybe 100 sheets) with the exact ink and paper combo. Measure the density and dot gain. Adjust the Komori’s ink keys and dampening system accordingly. The KHS Hyper System is great, but it’s not psychic. It needs good input data.

Check this: Are you using a standard color reference? Even a simple job should be compared to a color bar. Industry standard color tolerance is Delta E < 2 for brand-critical colors. I aim for under 1.5 for logo colors.

Reference: DIC color matching formula: The actual CMYK match for a custom brand color. If you don’t have a reference, use the Pantone Bridge guide, but always make a press proof.

Step 5: Get a Digital Blueline Proof (Or a Press Proof for Critical Jobs)

I know it feels like an extra step, but this has saved me more times than I care to count. A blueline proof shows you every piece of text, every element, at the exact size it will print. It’s not about color; it’s about layout and positioning.

Do this: For jobs with tight text, complex graphics, or multiple panels (like brochures), a blueline is mandatory. For spot color jobs, I ask for a press proof if the client is paying for it. For standard black-and-white work, a blueline is usually enough.

Check this: Is the text legible? Are all panel folds in the correct position? Is the barcode scannable? (We missed a barcode once. The entire run had to be trashed because it couldn’t be scanned in the client’s inventory system. That was a $1,200 lesson.)

Even after ordering the proof, I keep second-guessing. What if I missed something? I don’t relax until I’ve physically checked the first 5-10 good sheets off the press.

Final Notes: Common Errors I Still See

• Assuming all PDFs are print-ready. Even from professional designers. Always verify.
• Skipping the paper check. Especially for small orders where you think you can ‘just make it work.’ Respect the 100lb cover minimum for business cards.
• Forgetting about the bleed. This is a classic. A 1/8 inch bleed is standard, but some clients design with no bleed. That leads to white edges. I’ve seen it more times than I can count.
• Not cleaning the blanket. On a Komori running a high-coverage job, a dirty blanket can cause ghosting. We’ve caught 47 potential errors using this checklist in the past 18 months. That includes 8 blanket-related issues.

And one last thing: treat small clients like potential big clients. The $200 order today might be the $20,000 order next year. Don’t give them a reason to blame you for a preventable error. This checklist is my way of making sure I don't.