ALAR 6712  Studio Workshop Spring 2010

Workshop 10 Notes, March 4, 2010

Printing, Plotting, and Scanning

Color Management

-assigning and/or using a Photometric Color Profile (ICC Profile) for a given physical device (a printer, scanner, camera, monitor)

-computer screen (RBG) and placement on paper (CMYK)

A color space is a variant of a color model and has a specific gamut (range) of colors. For example, within the RGB color model are a number of color spaces: Adobe RGB, sRGB, ProPhoto RGB, and so on.

Each device, like your monitor or printer, has its own color space and can only reproduce colors in its gamut. When an image moves from one device to another, image colors may change because each device interprets the RGB or CMYK values according to its own color space. You can use color management when moving images to ensure that most colors are the same or similar enough so they appear consistent.

In Photoshop, a document’s color mode determines which color model is used to display and print the image you’re working on. Photoshop bases its color modes on the color models that are useful for images used in publishing. You can choose from RGB (Red, Green, Blue), CMYK (Cyan, Magenta, Yellow, Black), Lab Color (based on CIE L* a* b*), and Grayscale. Photoshop also includes modes for specialized color output such as Indexed Color and Duotone. Color modes determine the number of colors, the number of channels, and the file size of an image. Choosing a color mode also determines which tools and file formats are available.

Ways of getting consistent colors:

-calibrate monitor

-add color profiles to your system for any input and output devices you plan to use, such as scanners and printers

-set up color management in Adobe applications

-preview colors using soft-proof

-use color management when printing and saving files

Photoshop [color mgm't]:

1) Once you open the print menu, select Color Management on the right hand side. Make sure document is selected. Go to Color Handling. Select Photoshop Manages Color. You can then choose a printer profile available from the program.

[Optional]
If you would like to embed a color profile into the image for later use: When opening a new document in Photoshop, select the desired color mode. Open the Advanced option and select a color profile. If you do not see one that applies to you, select a default Photoshop profile.

 

InDesign, Illustrator, and Adobe Acrobat (Not Reader) have similar settings.

Photoshop (soft proof):

-View > Gamut Warming (A gamut is the range of colors that a color device can display or print)

-paper profiles

 

Printers:

-all icc profiles and instructions are automatically installed with the A-School Network Setup Installers for student laptops. They can found in:

Olmsted/Projects/Utils/icc profiles/

-The full network setup tools for printers, network drives, and color profiles, as well as other documentation and helpful tips are at:

http://www.arch.virginia.edu/computing/docs/

-UVA School of Architecture color printers, papers, and profiles reference:

It is always helpful to go and physically check the type of paper present in the plotter.

Printing Speed Optimization and Waste Reduction:

-Verify that your print job is going to the printer that you want. ~30% of our waste is due to this problem alone

-Expedite Plotting by keeping print jobs small

-Plot jobs look good on the wall for a review at resolutions as low as 100 dpi. A color 24" x 36" image at 300 dpi is about 210 megabytes. Reducing the resolution to 100 dpi will cut the job size to 24 megabytes! [ 1/9 the size ]

-Plot from InDesign or Acrobat

-PDF Optimizer in Adobe Acrobat Pro (Advanced menu) to reduce size and complexity of PDF files

-Plotting from PhotoShop sends all pixels as image data (including white pixels). If you are compositing multiple images and text, InDesign (and PDFs exported from InDesign) are smart enough NOT to send white space as image data. This can reduce the size of line drawings or drawings with significant amounts of white space ENORMOUSLY!

-Print vector data (lines, CAD) rather than raster (image) whenever possible. Vector data prints much faster.

-Print Black-and-White Images in Grayscale. Black-and-white images are 1/3 the size of color images. If your job has grayscale content only, change the mode in the Photoshop image menu to "Grayscale" before plotting.

-Rotate Plot Jobs to reduce waste, print time, and money!

 

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Contex Roll Scanner Instructions:

Before Scanning

1. Yellow power light on scanner should be ON, but all other lights OFF. Otherwise, Restart (See below).
2. No stickers, tape, dots or layers can go into scanner. Thin paper only.
3. If pastels or ANYTHING is on drawing that might rub off on scanner use clear acetate sheet from A&A supply to protect scanner from gunking up.
4. Insert graphic face down centered and straight until scanner 'grabs' the paper.

Scanning

1. Start Wide Image on Computer desktop
2. In Scan Setup set PRESET to None
3. MODE is graytone or 24 Bit Color
4. RESOLUTION is dots-per-inch
5. Set PAPER SIZE to AUTO PAPER SIZE (Click Arrow to RIGHT) so that AUTO IMAGE WIDTH shows.
6. Click GREEN CIRCLE to start scan.
7. CHANGE the location scan is to be saved to Temp drive: S: or T: and type in name. Note: Paper will roll down to check width, then pull back to top and then scan.
8. Push the BLUE down switch to push the paper out at the bottom of the scanner. Note: If streaks appear down the length of scan, scanner is dirty
9. Log out when done

To Restart Scanner

1. Power Off Computer
2. Power Off Scanner and count to 10 to allow motors to stop turning.
3. Power On Scanner
4. Power On Computer
5. Red lights will flash on scanner for 5 minutes - when only the yellow Power Light is on, Scanner is ready.

 

File Formats:

There are many different file formats that can be used to store image data. Some of them are very high quality yet very large, while others may be small but compromise quality. Which format you use will be dependent on what your image looks like, how much quality you need and how much space you have to store it in. The matrix here delineates some of the strengths and weaknesses of a few of the more common formats.

Generally, the Tiff format is best for use with line art or drawings where image quality is key and uncompromisable. Jpeg is best for working with photographs, where a little bit of loss in color quality, but not too much, is acceptable and not noticable.

TIFF Compression and Byte Order

When saving a file in the tiff format, for example, you will be asked to specify the files compression and its byte order. Compression allows the file to be compacted into a smaller data size while it is being stored on the disk; The file will then take less up less room and therefore more images can be stored in the same amount of space. For tiff image files, always choose the LZW Compression check box when it is presented to you. The byte order of a file is determined by the type of machine at which you are working, and effectivly corresponds to words being written forward or backward. The two options for byte order are IBM Compatible and Macintosh. Both machine types can usually read either, but if there is a question, always choose the IBM byte order. Macintosh computers are very good at reading the IBM language, whereas IBM computers will sometimes only read their own language.

File Size vs. Image Size:

File size refers to the amount of memory needed to store a given image document. File size is directly proportional to the number of pixels in an image; the more pixels, the greater the file size. File size also depends on the kind of pixels that comprise the image; e.g., since a full-color pixel needs more memory than a black & white pixel, a 1200 pixel "color" image will consume more memory than a 1200 pixel "grayscale" image. The file format of an image document can also affect its file size.

Image size refers to the actual dimensions of the image, as measured in inches (or centimeters). The dimensions of an image are independent of its file size: e.g., a 6" x 8" 2400 pixel will print out at the same size as a 6" x 8" 1200 pixel image (although the 2400 pixel image will have a higher resolution). Conversely, a 3" x 4" 1200 pixel image will print out at one quarter the size and twice the resolution of a 6" x 8" 1200 image, even if the images have the same file size.

 

Sources:

http://help.adobe.com/en_US/Photoshop/11.0/WSECCD001A-4989-4451-A752-63D5EF9D5619a.html

http://www.arch.virginia.edu/computing/docs/Color_Management_for_Printing_Summary.pdf

http://www.arch.virginia.edu/computing/printing/guidelines.php

http://www.arch.virginia.edu/computing/docs/

other useful sites:

http://www.udel.edu/cookbook/scan-print/gamut.html

http://www.udel.edu/cookbook/scan-print/gamut-hue-sat/gamut-huesat.html