How to format large prints for CAE plotters

CAE has two plotters available for printing black-and-white documents larger than tabloid (11" x 17") size, and/or color documents larger than letter (8.5" x 11"). One is in 1262 Mechanical Engineering, and is primarily used by people in the 1200 wing of ME, while the other is in 1249 Engineering Hall. If you want to look up specifications, the 1262 ME plotter is a Canon iPF 670 while the 1249 EH plotter is an HP Designjet T790ps 24in PS3.

If you are unfamiliar with using the plotters, or haven't used them in a while, improperly printing documents (particularly large documents) on them may result in extra cost due to incorrect orientation, and/or parts of the document being visually truncated in the final print. "Large" in this case meaning that at least one dimension of your printed document is greater than or equal to 24" (24 inches, or two feet), the width of the paper rolls our plotters use. This article will cover how to format your plotter print jobs to avoid these potentially costly errors.

While any given program with print functionality can send jobs to the plotters, here we're covering only the programs on CAE machines that are related to the most commonly printed file types. These document types are:

• PDF: Portable Document Format, typically opened with Adobe Acrobat Reader and similar programs. Many other document types can be translated into PDF format to create documents that anyone can view with free PDF reader software, plus potentially making these docs uneditable and flattening for easier printing.
  
  It's possible to create PDF files with a variety of programs on CAE machines, either by directly using the Save As function and selecting PDF, or by opening the print dialog and one of the PDF printing options. We'll recommend the Adobe PDF print option.


• Bitmap and JPEG images: There are numerous types of image files, including Bitmap (.bmp), JPEG (.jpg), GIF (.gif), PNG (.png), and TIFF (.tiff). The two most commonly used in plotter printing at CAE are Bitmap and JPEG images. Bitmap is a lossless, uncompressed raster image file. This means what you see is what you get, pixel for pixel, but file size is directly proportional to the image dimensions. JPEG is a type of compressed image file, trading various degrees of image degradation (not generally human-eye noticeable) for smaller file size.
  
  To directly print image files on CAE machines, open them with MS Paint, or for a bit more options, Adobe Photoshop. To access additional In the Print Dialog for Paint, you'll first select


• Powerpoint: .ppt and .pptx are both standard slideshow file formats used with the Microsoft PowerPoint program. People will often create posters for printing in PowerPoint because they're familiar with the program, and/or want to create multiple large slides. Unlike its .docx counterpart (see below), .pptx files are not limited to 22" x 22" max dimensions.


• Document: .doc and .docx are both standard document formats used with the Microsoft Word program. Keep in mind that the maximum document size in MS Word is 22" x 22".

A Note On Increasing Print Speed

Complex documents, particularly those with embedded charts, graphics, and/or many data points, usually take longer to print. There are a two ways to print a document of a specific size more quickly: first thing is reduce print complexity, and the second is to reduce print quality. If you want maximum print quality, then you'll have to reduce complexity instead. By first printing a document as a PDF (make sure to format your print size properly, as described in this article), you can then print that PDF with the Flatten Image option checked, as described in this KB article: https://kb.wisc.edu/cae/page.php?id=72166

A Note On Image Scaling

While you can increase and decrease the size of images and documents (AKA, scale up and down), beware before upsizing. If your image or document is smaller that the total dimensions you ultimately choose to print it at (limited by 24&no_frill=1" in one direction on our plotters), this will result in distortion as it "stretches" the pixels. This can be done in the Print Dialog window, either by choosing a Scale of greater than 100%, or choose to Fit to a paper size larger than the document itself. The further you scale your document up, the more blurriness will occur in the final print, so you may be able to get away with minor upsizing without noticeable quality degradation.

Two times this may commonly come up:

• If you pull images from a web browser, they are often very low resolution. Images designed for web are usually at 72 dots/inch density (mirroring standard monitor display density of 72 pixels/inch), while images designed for print are usually at 300 dots/inch density. In other words, images as they appear on your monitor will usually be roughly 1/4 the size if printed without any scaling (300/72 =4.167).


• If the program you created your document in has a default document size (like 8.5" x 11"/letter in Microsoft Word), if you neglected to change it and then try to increase the document size at time of printing, this may also result in pixel stretching.

The image included below shows an example of pixel stretching phenomena. The smaller image in the upper left is the original image size, 100%. The larger copy of the image on the right has been scaled up to 318% of the original, and is blurry by comparison due to the pixels being stretched so much. If you only upsize an image slightly, this will be less noticeable, particularly at a distance, but again, remember that the larger you scale something up, the more blurry it will get, unless you apply specialized upsampling software.

Setting up for plotter in Print Dialog

The process to set up a document has a few steps, and uses the Print Dialog in most programs. The image below shows the setup when printing a 24" (width) x 18" (height) PDF document from Adobe Acrobat Reader DC on a CAE lab machine, with number labels corresponding to the steps detailed below.

1. Open Print Dialog

Many ways to do this, but most programs will let you open it with the keyboard shortcut combination CTRL + P, or by going to the File menu and selecting Print from it.

2. Select a CAE plotter from list of available printers

If in Mechanical Engineering building, choose me-1262-plotter, or select engr-1249-plotter if in Engineering Hall. In the latter case, double check 1249's availability to ensure you can monitor and pick up your print without disrupting a class.

3. Access the plotter's Print Properties

How to do this varies by the layout of a given program's Print Dialog menu. For most programs, this will be the Printer Properties button (sometimes just Properties) located near the printer selection dropdown (MS Word, MS PowerPoint, Photoshop, Adobe Acrobat Reader). In MS Paint, it's instead the Preferences button. It's also a bit different in the Chrome web browser, where you first need to select "Print using system dialog," below the other printer settings, then select Print Preferences after selecting a CAE plotter. 

All of these will open a sub window with multiple tabs, the first of which is Paper/Quality, where we'll set Print Quality and Paper Options.

4. Set Print Quality to Custom Options

The Print Quality section has a few options. The first is an overall quality dropdown selection, which normally you'd select "Best (enhanced)" to get higher print quality. It'll take longer to print with this setting, but generally not too much, and the results will best match your source file. If you're concerned with speed over quality, you can select "Fastest," but only select this if you're OK with draft (test print) quality, or printing image with text/lines only. Otherwise, usually stick with "Best".

The second option is "Optimize for." You can optimize for Drawings/Text (like line diagrams)/Text, or for Images (like photos).

The third option is a checkbox for "Maximum detail." Recommend checking this box if you have complicated and high quality images/photos, or if you have lots of small, clean details (high density graphs or lines). If your print is mostly large shapes though (thick pie charts or bar graphs, for example), or if you're using source images that are a bit blurry, checking this box won't be much use (and may even be detrimental in the latter case).

In summary...

• For complicated images (a photo) select Best, Images, and check Highest Detail
• For simpler images (color blocks or diagrams) select Best, Drawings/Text
• For very simple graphical prints or layout test drafts, select Fastest

5. Make note of the paper size

Under Paper Options, make note of the paper Size. For example, the default document size, Letter, is 8.5" x 11". Compare it to the document preview just to the right, which is an illustration of the printed sheet's dimensions. We will use this in the next step to determine the required custom paper size.

6. Set up a custom paper size

Just beneath the Document Size section at the top, select Custom button. In the Custom Paper Size subwindow that opens, input the size of paper you want to print on. Up to a 24" (length and/or width) document, enter the larger dimension in the first field (the width field). Otherwise, enter the smaller dimension first, then the largest. The reason is thus: the plotters automatically interpret the shorter dimension as the width of the document, so to save on paper use (and thus, cost to you), if neither side of your document exceeds 24", enter the larger of the two as the width in the Custom Paper Size.

There are a couple differences for the 1249 EH plotter: you need to define a name for your custom paper size before the dialog box will let you save it. Change it from "Custom" to whatever makes sense to you. Also, the 1249 printer will not accept custom paper sizes where the width > length. To work around this, you'd need to set up your custom print size to the opposite of what's intended (for example, a 24" width and 18" length doc needs to be set to 18" width and 24" length). Then back in the Printer Properties subwindow, you need to enter the Features tab, and check the "Rotate by 90 degrees" box in the Roll Options section. 

7. Verify your custom paper size works as desired

There are three ways to check this. The first is looking at the Size vs. Printable Area (7A on the example image). The second is to check the Print Preview's dimensions vs orientation (7B on the example image). The third is to check print projected print cost vs. expected print cost (7C but not in the example image)

7A. Check Size vs Printable Area (margins size)

Look at the "Size is:" and "Printable area is:" section of the Plotter Properties dialog box, labeled 7A on the example image. The Printable Area dimension that will come out of the plotter length-wise will be reduced by 1.34" due to default margins, so watch for that to determine if your document is oriented as desired.

If your document is over 23.61" in width, be aware that it will be reduced in that dimension as well. The plotters use a roll of paper 24" wide, and long enough for effectively any CoE application. They are, however, not set up to print all the way to the edges of the paper. The effective maximum width is 23.61" (a roughly .2" margin on both sides). There will also be a 2/3" (0.67") margin on the leading edge (the edge coming out of the plotter first) and trailing edge (the edge that the plotter cuts when it's done printing). So for example, if you tried to print a 24" x 18" document, your printable area is instead 23.61" x 16.66," and to avoid part of your document being cut off, you'd need to select Fit or Shrink oversized pages from the Paper Sizing and Handling section of the main Print Dialog box.

7B. Check print preview

In the main Print Dialog box, you'll usually see a preview of the image. Make sure that your document is visually set up like in Step 6: Up to but not greater than 24", the larger side should be the width. If one side is above 24", then that side should instead be your document's height. In the example document image, the largest dimension is less than or equal to 24 inches, so it's set as the doc's width. 

7C. Compare printing cost vs. expected printing cost

The final way to test if a print document has been formatted as desired is to open the print release queue and see how much the document costs, before releasing it. It costs $1.80 per linear foot (i.e. how much the paper roll has to spool out, length) on CAE printers, or $0.15 per inch. So to check, multiply the expected inches and/or feet by the cost to get the final cost. For demonstration, the example document is 24" wide x 18" long, so (18") x ($0.15/inch) results in a document that costs $2.70 to print on the plotters.

If this amount is greater than or less than the expected cost, something went wrong. You may be able to troubleshoot by dividing the cost by cost/inch to figure out how many inches the doc's length is. For further demonstration, the example doc (intended to be 24" width x 18" long) were charging you $3.60 and not the expected $2.70, then dividing that by $0.15/inch tells us the job would be charging for 24". More often than not, what goes wrong is that the document isn't oriented properly (typically during Step 6), resulting in intended width and length being swapped, so watch for that.