What are the pros and cons of digital printing?
- Up to 80 impressions a minute
- Little setup time
- Use of variable data
- Output is printed on both sides, dry and ready for any bindery work
- Colors are bright and brilliant
- Images are crisp
- Toner layers
- Dark inks are always glossy
- Cannot print on stock under 50# or on stock over 130#
- Cannot run plastic or metallic stocks
- Cannot run standard envelopes
- Cannot accurately match most Pantone colors
- Printed pieces cannot be imprinted or printed on with customer’s laser printers
How to choose between offset and digital printing:
Typically, quantity (because of cost) is the most deciding factor between digital and offset, second only to deadlines.
- Better and more cost effective for larger runs
- The right choice when a specific Pantone color or metallic ink must be used
- The choice when the stock sheet size exceeds 13” x 19”
- Necessary if the chosen stock is heavier than 130#
- If the printed piece must go back through a customer’s laser printer, you need to use offset printing
- More cost effective for shorter runs
- Perfect for shorter runs with multiple originals – even with different quantities of each
- When a short deadline must be met
- When the job uses variable data
Is all digital technology the same?
There are definite differences between digital technologies and digital presses. Some presses utilize a fuser technology that creates problems if the printed piece needs to be coated with UV or varnish, or will be laminated. There are also different qualities of toner used, depending on the manufacturer of the digital press. The finer the toner particle is, the cleaner, crisper the output will be.
Xerox grows their own toner particles, for a uniform size and very high quality. Xerox uses 2400 x 2400 DPI (dots per inch) while other digital press manufacturers use 1200 x 1200 DPI. The higher DPI allows for higher line screens and better image quality on the printed output. Xerox has the the ability to use a clear dry toner—our digital printer is one of only three XC800 presses in the state of Wisconsin that offers clear dry ink.
What size sheets can be run on the digital press?
7.5” x 7.5” up to 13” x 19” – the image size needs to be 4-8 mm smaller as there is a 2-4 mm “no print” zone on all four sides.
What weights can the digital press handle?
55 to 359 gsm (or 50# bond to 130# cover)
What is the best file for digital printing?
The perfect file is a flattened PDF.
How do I need to set up that file?
Create/output the PDF as a high resolution and high quality file. Make sure that all graphics are either grayscale or CMYK images. Make sure that black type is really black and not made up of RGB or CMYK. If the document contains drop shadows or uses transparency, then it the file needs to be “flattened”. Our Prepress Department can work with you and explain how to do that. It is unnecessary to use trim marks or a color bar when outputting the file, just make sure if the document bleeds, make sure there are bleeds in the file.
What I see on my computer is what I will see printed on paper, right?
No, not necessarily. Every monitor is different and the same file will look different on each. This is also true with Digital output. The file may look one way on your monitor but after the file is processed through the DFE where the image is “ripped” (or rasterized). When the color is not a solid cyan, magenta, yellow or black digital printing is made of dots of those colors to make all other colors.
Why do colors differ from offset printing and digital printing?
While both offset and digital use CMYK print with, the difference between ink and toner mediums will cause a slight different look to the printed piece. Offset and digital are rasterized through two different rasterization (or RIP) systems which also case variations in color – especially if the file happens to contain RGB elements.
Why can’t a digital press print a true match to a Pantone color?
Digital printing uses only CMKY toners so if the document uses a Pantone and/or a metallic color, the DFE must translate those colors as close as possible using CMYK. While it the translation will come close to most Pantone colors, there are some (like fluorescent colors) that digital printing just cannot match.
What do I need to know about setting up my data file for variable data printing?
All variable text, barcode data, variable graphic names, anything that will be needed to create the variable data on the final printed piece needs to be supplied in a data base or mailing list spreadsheet. Use the first row of the data file to title the columns/fields. Every data base column represents a different variable field used in the layout. Each row under the header is a record and equates to all the data needed to complete a variable data printed piece. If your project pulls data from multiple data files/lists, sort and merge the data together into a single data file. Delete unused fields. Don’t put the entire address in one field nor separate the address completely out where the house number is in one field and the street name is in another. Provide your data in upper and lower case letters. Be consistent in data entry. Proof your data and review it for accuracy, omissions and duplications. Save out as an Excel file (.xls or .xlsx), comma separated file (.csv) or tab delimited text file (.txt). The text file is the least preferred format but usable if setup and output correctly. If variable graphics/pictures are being used, make sure that they are all provided along with the list. We can create most barcodes from you data file (e.g. postal codes, UPC, Data Matrix, and QR).
What are the requirements for images and graphics for printing?
When designing digital files intended for commercial offset printing, it is essential that all of the photographs and images in your in files are at least 300 dots per inch (DPI). If you have ever seen printed material that contains blurry or blocky images, it was likely caused by incorporating low resolution images. Ensuring a high quality printed job is as simple as making sure all photos and images in your digital files are all high resolution.
All artwork design programs allow you to resize an image you are working on, but it's important to understand why simply resizing a low resolution image will not produce a true high resolution image. When you resize and make a low resolution image larger to meet the commercial printing specifications of 300DPI, all you are really doing is stretching the image. The technical term is called either resampling or interpolation. Since high resolution images are based upon the number of pixels an image contains, resizing will not create new pixels, and will only make each pixel larger by stretching it. The only way to ensure picture perfect high quality printing of your photos and images is to start with a high resolution image.