|Preflight: The first step in producing a job at Bokland Custom Visuals|
When a file is submitted to Bokland Custom Visuals for reproduction, whether it is being output on our LightJet 430 printer, our Gandinnovations 1224 UV Cureable Direct to Substrate printer or any of our other large format printers, the first step is preflight.
Preflight is the process where a qualified technician checks the files submitted for a project to make sure they meet all requirements necessary and that all necessary elements for proper printing are included. This step ensures that we can meet the clients deadline and also create a finished product that meets the clients expectations.
Some of the criteria we look at includes: proportions, image quality, resolution, fonts and many others. Once the file has passed our preflight process we can proceed to create a quality large format product on our LightJet 430 printer, our Gandinnovations UV Cureable Direct to Substrate Printer or any of our other output devices.
Bill Booth - Graphics Specialist, Bokland Custom Visuals
ICC Workflow: Embedding Profiles
One of the first steps in a color managed workflow is choosing an input or editing color space sometimes also referred to as a work space. Input profiles determine a color range or gamut you can work in and they are device independent.They allow you to edit your images in a controlled and consistent manner. Input profiles are used in image editing programs such as Adobe Photoshop
Two of the most commonly used input profiles in digital photography are Adobe RGB 1998 and sRGB IEC61966-2.1. The default in most programs is sRGB. This is the common profile used for preparing images for the internet. It has a smaller color gamut and can simulate color consistently on different monitors. If you are planning on printing your image on a large format printer like a LightJet or high end inkjet, you're better off using a profile with a wider color gamut like Adobe RGB or Colormatch RGB. While not all the colors within these profiles are printable they will give you larger and more pleasant range of colors to work in, and better results.
To set up input profiles in Photoshop CS4 go to:
Menu > Edit > Color Settings
Here's a really important thing to remember -
All your work is for nothing if you don't embed the profile when saving.
The profile you choose to work in needs to stay with file, so when its re-opened
or sent to a printer the colors will display and convert in a consistent manner.
Paolo Desanctis - Graphics Production
A pixel is the smallest measurable interval of a digital bitmap image. Resolution is a measurement of pixels. It determines how an image will appear on the screen and how the pixels are distributed in the output, or how the pixel information will be used on a printer. The original pixel dimensions of an image are determined by the capabilities of the hardware that was used to capture the image, usually a digital camera or scanner. More captured pixels in an image means more detail, better gradations and depth of color.
Like many other things in a digital workflow resolution can be thought of in two ways: input and output.
Input is the capturing of pixel information weather through a digital camera, scanner or created/rendered with bitmap image software.
Output is how that captured information is going to be used or distributed. On a monitor, projector, television or output through a printer to paper, canvas, wood, metal or any other substrate.
Even though they are often used interchangeably, pixels per inch (PPI) and dots per inch (DPI) are not the same thing. PPI refers to the number of pixels found in one inch of a digital image or a monitor. DPI refers to the amount of resolution a printer is capable of outputting. Printers use dots of ink to render an image; the more dots a printer can produce per square inch (DPI), the better its quality. The finer the dots and the pattern by which the dots of ink are laidd down also contribute to the quality of the printed image. But this is only half the equation. No matter how great the printer resolution is the quality of output will be determined by the resolution of the original capture. In an ideal situation you want the needed input resolution for the intended output.
Lets say you're working on a large trade show exhibit with multiple images from multiple sources and the main part of your exhibit is a large paneled wall printed about 8 feet by 10 feet. It would be best to set up and edit the images to output size before beginning any layout or design. This will give you an idea of how big you can go and possibly save you from having to rework anything later for lack of resolution. Viewing distance is a key factor in determining how big you can go. It is best to speak to a technician for information on resolution guidelines, but most likely this will be anywhere from 100 DPI to 300 DPI at actual print size for most printers.
To see how much image resolution you have for your intended print size open the image size dialog box in Photoshop under the image menu.
Here is a 10" x 15" image at 180 ppi resolution. Uncheck the resample box and enter a new document size.
This resizes the image and changes the image dimensions without changing the total pixel dimensions. Note how the pixel dimension is locked out and doesn't change. Here at 20" x 30" the resolution is 90 ppi. By doubling the document size the resolution is cut in half. Essentially the original pixels of this image are going to be distributed further apart to cover the new larger size. This also works in reverse when scaling down an image. Making the size smaller gives you more pixels per inch. If you check the resample image box and change the dimension size the software uses interpolation to create new pixels, in effect adding pixels to the image. The interpolation process estimates the values of the pixels needed based on the existing pixels in the image. Interpolation can introduce a loss of quality even though it is adding pixel data. This depends on the quality of the image that is being resampled and the amount of resampling being done. The trick is to use it sparingly. It only really works if the original pixel data is of good quality, sharp, not grainy and not compressed. Then you have a shot at increasing your pixel dimension 15% to 25%. Another tip would be to size up in increments of 5% to 10% at time rather than all at once. This allows the software to make better estimates on the new pixel data. Image resolution is a complex subject matter with many facets. Hopefully this will bring some light to the base concept and be of aid in your next large format printing project. Paolo DeSanctis Graphics Production
Soft-proofing is an on-screen simulation of how your image will look when output to an inkjet printer, substrate and ink combination or an RGB printer like the lightJet. It is based on an output profile of that device made especially for a that substrate and ink combination. A calibrated monitor is crucial for viewing color accurately and soft-proofing can take your images and color control to the next level. A printer can not reproduce the entire range of colors that are viewable on a monitor, these are known as out of gamut colors. Each printer, paper, ink combination has its own gamut or range of reproducible colors. There may also be a shift in color balance from what you see on your monitor to the print. If you’re sending images or a design project to a printer for output on their LightJet or large format printer, the need for proof prints can be minimized with soft-proofing and you can identify what colors may need a little attention. To soft-proof your image in Photoshop, select View > Proof Setup > Custom. The Proof Setup dialog box will pop up, in the first drop down select the profile for the output you’ll be using. You can request this from your printer or photo lab. Next, select a rendering intent. These are the methods by which out-of-gamut colors are mapped from the working space to the gamut of the printer, paper and ink. Perceptual works well for most images especially if there are many out-of-gamut colors. Relative Colorimetric can be better choice if your image doesn’t have any colors that are out-of-gamut for the intended output. Meaning there is less interpolation in the mapping of color to the output device, where as Perceptual there may be more interpolation in mapping colors, attempting to preserve the relationship of colors inside and outside the output gamut. Black Point Compensation should be checked, this ensures shadow detail will be maintained in the output gamut. The Simulate Paper Color and Black Ink check boxes add a simulation of the whites and blacks of the profiled paper and ink. When a printer profile is made the color of the paper is one of the factors in building the profile, because the spectrophotometer is reading the combination of the ink, and the paper below it. These can be helpful if you are printing on off white or tinted substrates. When you click OK, you will see a simulation of the image printed through your output profile. To toggle between the proof simulation and the normal view press Ctrl-Y. Soft proofing can be a very valuable tool when preparing images for your trade show exhibit, POP poster or décor project. Feel free to email with any questions or to request one of our output profiles. Paolo DeSanctis Graphics Production
If your looking for consistent color from your large format print vendor or photo lab, calibrating your monitor is a must. A monitors color output varies even from out of the box and especially over time as they age. Calibration keeps them operating in a stable and consistent way. Hardware monitor calibration is the best and most accurate way, and in recent years has become much more affordable. You can pick up a monitor calibration package from a leading color solution company like X-Rite for around $200. 10 years ago this sort of technology cost thousands.
Hardware based calibration uses light monitoring and measurement devices (spectrophotometer) with color management software to achieve more exacting and consistent results. With hardware calibration the red, green and blue phosphor colors, as well as the white points, are all accurately measured and corrected to an industry display standard. Re-calibrating every 2-4 weeks will maintain the monitor so that the way it produces color will stay consistent over time. If your monitor is not correctly displaying color, then time spent on image editing could actually be counter-productive.
Adopting and maintaining a monitor calibration and color management system will guarantee the results on every trade show, large format print, and POP display project that you work on, saving time money and frustration!
Regardless of wether you are making a ten foot Trade Show booth, Point of Purchase Graphic, Vinyl Banner or a Wooden Sign, a hard copy will make your job go smoother. Even if your hard copy is in Black and White it can help us catch any errors that can occur in our process. You have all ready done your work of providing your fonts (We recommend outlining fonts) and related graphics. Now we have to process your file in our RIP Software for printing. In the case of Indesign or Quark we may have to create an intermediary file like a PDF or an EPS for processing. Many things can go wrong. Fonts can sometimes can drop out or be replaced with a font of a different manufacturer. Spot colors used with transparency may yield unexpected results or even elements within you file may completely drop out. All of these things, and more, we can catch more quickly with a hard copy. With most jobs we recommend getting an approval print, but a hard copy can help avoid a second approval, saving you valuable time and money.
When submitting a file to Bokland Custom Visuals that contains text for large format graphic output, there are steps you can take to insure that your project is completed on time and to your expectations. Providing us with all the fonts used is one step. Also, many graphic applications allow fonts to be converted to outlines. Whenever possible, providing files with fonts converted to outlines is the safest way to go. Once you convert all fonts to outlines it is no longer necessary to provide us with the fonts used.