I believe there is a huge misunderstanding that exists in our industry regarding printer speed. Okay, “huge misunderstanding” is maybe a bit strong, but a “mis-perception” exists to be sure. Of course it’s true that printer speed is a very important consideration, but it’s more helpful to understand and exploit the factors that determine speed. 

 

Printer output speed is almost always listed in terms of square feet of output per hour (square meters per hour in Europe). But simply looking at square feet per hour doesn’t tell you anything about the factors that go into making that speed, and that’s where the real value is. Besides, the only speed that really matters is linear inches per minute. What’s really important is that you maximize your printer to get the maximum linear inches of output per minute, and still deliver quality. Let’s look at some important print-speed factors and examine how your printer’s speed can be used to best advantage.

 

Here is a close-up view of a print running at 720 x 720 dpi at eight-pass.  Note how bands get more defined as they print. After the eighth pass the green is solid.

KEY FACTORS

There are a number of key features that every printer has that contribute to the quality and productivity of that printer (I am not considering dot size here because such a large number of printers don’t allow for selecting drop size).

 

• Resolution

• Number of passes

• Carriage speed

• Head size

• Print modes

 

Resolution—Print resolution is based on a the number of individual dots of ink that appear within a square inch of full coverage print—dots per square inch (dpi). It is measured both horizontally and vertically, for example 1440 x 720 dpi. Sometimes the first figure is larger than the second. That’s because since the printheads are perfectly aligned along the printhead carriage, and they print more efficiently and accurately shuttling left and right versus up and down as the media advances. 

 

It is also true that all images look better at higher resolutions.  For example one of my printers supports 360 x 360, 360 x 540, 720 x 720 and 1440 x 720 dpi. But it’s interesting to note that that the lower the resolution the faster the printer can print. The print mode I like is 360 x 540 dpi; the printer runs at approximately 6" per minute.  In other words in one hour I can print 30 feet of material. Printing at this resolution allows me to print one full car wrap in two and a half hours!  

 

Here is the Onyx RIP screen that shows the past jobs on the bottom, and the running jobs in the center. The resolution column shows you what mode you have each job in.  The printer will automatically change modes as the RIP defines.

What is very interesting is that the 360 x 540 dpi produces what to me looks very much like the same quality as the 720 x 720 mode, yet it’s much faster. Of course differences become obvious when you print very small type, but for 90 percent of what I print, 360 x 540 dpi is just fine. I don’t run this resolution all the time because only half the heads fire at this speed so I get more ware on the heads and only draw from one half the ink tanks. Find a sweet spot of print resolution that will satisfy your client and still allow you to print fast.

 

Number of Passes—Passes refers to how many times the printheads have to pass over the image to achieve the full resolution. On most printers, each pass will put down a series of lines of ink, and as these lines are passed over one another, they produce a perfect image. The more the passes made by the printheads the better the print quality—and the slower the print speed. 

 

The trick is to run as few passes as possible without sacrificing print quality. But cutting down the passes to much will result in banding. Note: banding can also be caused by improper media stepping, clogged nozzles or other issues. 

 

Here is the drop-down box in Onyx that allows you to change the print mode per job. This can have many options but I feel you only need one or two at max.

Carriage Speed—Carriage speed refers to the speed that the printheads travel back and forth along the print carriage. Most printers allow you to run the carriage faster for lower resolution print jobs. To maximize speed, run the carriage as fast as you can without sacrificing needed print quality. In most cases you can control the carriage speed from within the RIP.

 

Printhead Size—It makes sense that the size of the printhead makes a huge difference on speed because, wider printheads have more inkjet nozzles delivering more ink across a wider area resulting in a wider band for each print pass.  

 

Some of the new printers have very wide printheads—some as wide as 4", so each pass is 4" and the average printer runs at one pass each four seconds, so a 4" wide printhead could produce about 5' per minute or 300' per hour! When it comes to printheads, bigger is usually better. 

 

Print Modes—Depending on the RIP you are using, you should be able to set up the modes you need to run your printer at the best speed.  I use two modes. For most jobs I run at 720 x 720 as this mode is just about perfect.  At this mode the speed is 3.5" per minute.  Then I set up a fast mode for jobs that the resolution of the file is not high, or the job is for a farther viewing distance (vehicle wraps) or the time does not allow for the high resolution mode. The fast mode (360 x 540) I run at 6" per minute. In my RIP I have the option when opening the files to choose the mode to print the job. In most cases you will need to have a different color profile for the different modes.

 

Although printer speed is very important, controlling the factors that determine speed will also allow you to meet your clients’ quality needs. (Image courtesy of Seiko I Infotech)

MAKING MONEY WITH PRINT SPEED

So, how does all this printer speed make you money? The only rule you must always remember is that if your printers are not running you are not making money!  It is always best to purchase a fast printer so when those large jobs come along you can get the work done on time.  

 

Still, you should know the speed of all your printers based on linear feet per minute. Armed with this knowledge, you can write on each job ticket the total time to run each job. Then, at any time during the day you can look at the job tickets for any printer and determine in a few minutes how much work you have for that printer that day. This allows you to schedule your help better, control overtime and help keep jobs on track.  

 

Let’s say you have a printer that runs at 720 x 720 and you get 2.5 inches per minute at eight-pass. If you hire a person to come in and create profiles for your printer at both eight-pass and four-pass, it will cost you $600. Is it worth it?  

 

Let’s do the numbers. At eight-pass you are getting 2.5 inches per minute, but at four-pass you get 5 inches per minute. Before you made the change by adding the new profile and speed, each hour you can print 12.5 linear feet, but after the new profiles you can now print 25 linear feet per hour. Now a job that needs to produce 120 3' x 5' banners that would have taken more than 28 hours can, with the new profiles, be done in 14 hours.  

 

In this way you can double your output per day, and I calculate you can now triple your profit per year. So, the message I have for you is that you should set up your printer to the fastest mode that you can sell, and unless the job requires the lower speed (due to small type or difficult solid fields of color) you should always sell this quality and run all jobs at this fast speed.

 

So I would say the $600 was worth it, right?

 

Okay, good luck, be smart with your money, and I will see you on the show floor!