coroplast signs direct-printed with MUTOH VJ626UF printer

There’s a lot of talk about essential business these days. When there’s so much changing all around us, it seems to me that signs are more essential than ever. Restaurants need to advertise curbside pickup and drive-through options, service industries need to engage customers, and there are nationwide elections looming. It all adds up to opportunities for sign blanks. It’s a good time to consider ways to generate more appealing signage more efficiently. One of the best ways to do this is with direct-to-substrate printers like the MUTOH ValueJET 626UF. The VJ626 UF is a UV-LED printer that prints directly to a myriad of hard surface items. Although direct printing coroplast sign blanks isn’t its primary function, the VJ626UF can also be used for direct to substrate sign printing. There are some advantages and disadvantages, caveats and considerations. Here’s what you need to know.

Mutoh 626UF overview

The MUTOH ValueJet VJ626UF is a tabletop UV-LED printer that prints on solid objects up to 5.9 inches thick. The printer uses UV-cured ink in the traditional CMYK process color gamut plus white ink and varnish. The white and varnish inks add capabilities for printing on clear and non-white substrates including plaques, wood, and colored sheet media such as acrylic.

The 19” x 23” bed size is just about perfect for yard signs and covers a wide range of other profitable applications. Like all modern MUTOH printers, the ValueJET 626UF is powered by an advanced micro-piezo print head augmented by MUTOH’s patented intelligent interweave technology. The I2 algorithm lays down ink in overlapping wave patterns that virtually eliminate banding. The result is an efficient blend of speed and quality. There is an optional rotary attachment that supports printing directly to tumblers and sport water bottles. 

MUTOH’s LUH1 and UH21 inks are ideal for rigid substrates. As noted above, white and varnish support printing to clear and colored items. For the purposes of this article, we’re dealing with good old CMYK.

Direct Printing advantages

Why should you consider direct-printing sign blanks? There are several reasons, but the main advantages are quality and efficiency. Anyone in the modern sign industry knows customers want the higher appeal of digitally printed graphics. There is a commercial market for signs with spot color vinyl, but it’s not growing.

Customers prefer digitally printed graphics because they add gradient color and photographic elements to the designer’s toolbox. They’re just more appealing and therefore, more effective. Sign makers prefer digital printing because it eliminates the chores of weeding vinyl and applying it in layers one color at a time.

Most of our customers who digitally print signs are mounting printed vinyl to sign blanks. This is a tried and true method that has its advantages, including a much lower equipment cost. Digital direct to substrate printing takes the efficiency advantage one step further. You get to skip the steps of trimming the vinyl, masking and mounting it to the substrates. Just load your substrate, print it and you’re done. So, if you have the right kind of printer, direct printing sign blanks is an attractive option. And, if you have a MUTOH 626UF, you have the right kind of printer.

The ValueJET 626UF is a slam dunk for decorating non-traditional substrates and hard surface items like tumblers, plaques, awards, cell phones, etc. But what about traditional sign industry applications like real estate signs and yard signs?

Yes, but: Direct Printing Caveats and Considerations

Yes you can use a VJ626UF to direct print traditional sign blanks, including 18” x 24” aluminum and corrugated plastic. But, there are few caveats. Here are the things to consider as you size up this opportunity.

Size: The VJ626UF has a 19” x 23.3” bed. Since it’s almost an inch shy of the actual width, full-bleed edge-to-edge graphics aren’t an option. This is not a huge problem. Just design your sign blanks with adequate negative space and borders. The upside of this is lower ink costs.

The Static Problem: The primary challenge for direct to substrate printing on plastic blanks is static electricity. This is especially true of stacked sheets of corrugated plastic. The static charge interferes with the dispersal of ink droplets jetted from the head and causes overspray (Fig 1). MUTOH recommends using a staticide or some other tactic to reduce or eliminate static electricity before printing.

staticide cures over-spray on plastic sign blanks for direct printing
FIG 1: Isopropyl alcohol and staticide defeat overspray

The Static Solution: We used a two-step prep that includes isopropyl alcohol and a common staticide. Treating with staticide only doesn’t always work. But cleaning with iso first, then treating with staticide produced consistently outstanding results in our demo room. Static charges are also a function of climate and aridity, so depending on your region and the time of year, your mileage may vary. Click here to download MUTOH’s supplement with detailed strategies for knocking out static electricity.

Durability: The final caveat to direct to substrate sign printing with a VJ626UF is UV resistance. Despite the name, UV-LED ink is not the most outdoor- durable option. Eco-solvent ink is much more UV resistant. UV ink on coroplast should only be considered for short-term signage. Election signs and promotional signs are the ideal application. If your product needs to be out in the weather for more than 6 months, you should defer to an eco-solvent roll-to roll printer and stick with mounting your signs to substrates (pardon the pun).

Or, if you’re sold on the direct-print option and want something more durable, you might consider the MUTOH 1638UH, which uses MP31 multi-purpose ink. MP31 offers the versatility of UV and the outdoor durability of eco-solvent. The 1638UH is a larger investment, so sharpen your pencil and do your homework before you sign on the dotted line.

Time & Money

Speaking of investments, let’s look at the business case for direct printing yard signs. How efficient and cost-effective is it compared to roll-to-roll printing? The VJ626UF is engineered for decorating items that will be viewed at arm’s length. Because of this, the bundled ICC profiles in the MUTOH Edition Flexi Sign & Print RIP are tilted toward quality over speed. The out-of-the-box print modes aren’t necessarily the most efficient way to crank out yard signs. If this is going to be a large focus of your day-to-day operation, you may want to create a custom ICC profile. We used the existing Quality 1 and Banner 2 print modes on our test samples with excellent results (See slide-show below).

    Time: Again, since this isn’t what the machine was engineered for, the print speed isn’t blindingly fast. Timed from the beginning of throughput from the RIP to completion of the print job, a typical 18 x 24 sign takes about 15 minutes to print. More saturated graphics can take a little longer. Our Hot Iron BBQ graphic, which is pretty close to full coverage, was done in 17 minutes. Our Proposition 8 sample sign, printed at Banner 2 took just over 15 minutes per panel. So, a half day printing would produce about 16 sign blanks.

    Money: The ink costs for our signs range from 28 cents to $1.15 depending on ink coverage and print modes. Add $1.50 or less for the sign blank and you have a total cost of well under $2.00 for a high-quality sign worth $15 or more, depending on your market. Here are the time and money specifications for the samples made for this article.

    Hot Iron BBQ Sign - slide 1 above

    • Print mode: Graphics 1 720 x 1440:
    • Print time: 17 minutes.
    • Ink Cost: $1.15. Total Material cost, $2.65

    Seniors 2020 Sign - side 2 above

    • Print Mode: Banner 2, 720 x 720:
    • Print time, 16 minutes, 47 seconds:
    • Ink Cost: 38¢. Total Material Cost, $1.88.

    Election Sign - slide 3 above

    • Print mode: Banner 2, 720 x 720dpi:
    • Print time, 15 minutes.
    • Ink Cost: 28¢. Total Material cost, $1.78

    So how does direct to substrate sign printing stack up to traditional roll-to-roll printing in terms of productivity? Pretty well actually (FIG 2). To get an idea of just how productive the direct-to-print method is, we ran a comparison test using a PrismJET VJ24. We printed the Seniors 2020 image in the same size, on glossy vinyl and mounted it to a coroplast sign blank. To keep things fair, we used a comparable, high-quality print mode. The Seniors 2020 vinyl graphic was printed at 720 x 1440dpi. This isn’t the fastest mode for glossy vinyl signs, but it gives us a good head-to-head comparison of technologies.

    The print speed of the VJ24 is much faster. The Seniors graphic was done printing in just under 4 minutes. But you still have to trim it, pre-mask it, then mount it to the sign blank. All of this takes about 10 – 12 minutes depending on how efficient you are. Here’s the roll-to-roll time and money summary.

    roll-to-roll vs UV direct print comparison
    FIG 2: Roll-to-roll vs UV-LED Direct printing. The VJ24 print is the one on the left.
    • Print Mode: Quality 4, 720 x 1440 dpi
    • Print Time; 3 minutes, 57 seconds
    • Finishing Time: 12 minutes, 20 seconds (trimming, pre-masking, mounting)
    • Ink Cost: 29¢, Media Cost, $1.77
    • Total production time: 15 minutes, 57 seconds: Total material cost: $3.27

    There you have it. Despite the fact that 15 minutes sounds like a long time for the 626UF to direct-print a yard sign, it’s comparable to the total production time for printing and mounting vinyl. Proponents of roll-to-roll printing might be crying foul because I didn’t include the time needed to prep the sign blanks for direct printing. That’s true, but it takes less than a minute per blank and there’s plenty of time to prep the next one while one is being printed, so the impact on productivity is negligible.

    These are rough estimates based on our one-person sign shop scenario. The point is, direct to substrate printing can be a great time and labor saver. Add in the simplicity of direct printing, and there is definitely a business case to be made for printing yard signs & real estate signs with a UV-LED printer.

    Our novel coronavirus climate presents lots of challenges, but in every challenge, there’s also an opportunity. Signs for curbside pickup, novel ways to celebrate the Class of 2020, and looming nationwide elections are just a few. Direct printing to sign blanks with a MUTOH UV-LED printer makes a lot of sense. It saves time and simplifies your workflow. There are less expensive options like the PrismJET VJ24 and more robust options like the ValuJet 1638UH. But if you need an efficient way to print 18 x 24 signs for short-term use, the MUTOH VJ626UF is a right-sized solution. If you’re lucky enough or smart enough to already own one, you might want to add direct to substrate sign printing to your product offerings.

    *The PrismJET VJ24 material cost figures are based on current cost of PrismJET 203 glossy vinyl and EnduraMASK MHT 130 application tape at time of publication of this article.
    Ink cost estimates were generated using Flexi 19's ink cost estimator module, based on current SIGNWarehouse wholesale prices for MUTOH LUH1 220ml ink cartridges, and SIGNWarehouse wholesale prices for single sheets of white coroplast sign blanks.