Note that the information below pertains to the installation as it existed at the ACC, so some of the details may be outdated, but much of it remains valid.
Question: How can I print text or graphic files as large posters on the HP DesignJet Color Plotters?
This document shows you how to send plots to our large HP DesignJet printers. The first half contains material that is common to all of the software packages which create graphics for the printers, whereas the remaining sections treat issues that are specific to certain packages, such as PhotoShop or PowerPoint.
It is very important to note that in the instructions below, you must, in many cases, follow the exact same steps as appear in the examples or discussion. That is, in general, you cannot interpolate or extrapolate the instructions. For example, if you can scale an 8.5x11 inch image by 400%, it does not necessarily mean that you can scale a 17x22 inch image by 200% and get the same results -- the image may be printed part way off the page.
C&C currently has two large HP DesignJet printers: an HP DesignJet 650C and an HP DesignJet 755C. Both plotters can print images up to 108 x 36 inches in size at 300 dots per inch and are nearly identical except that the HP755C (a) prints truer colors, (b) offers a variety of output media, and (c) can handle Postscript Level II. The maximum size of a plot is partly determined by the software package which creates the image. The plotters only accept files formatted in PostScript, encapsulated PostScript, or (for the HP755C) PostScript Level II.
In the remainder of this document the terms "printer" or "plotter" refer to either of these HP DesignJets unless otherwise noted.
The plotter output costs $1 plus 10 cents for each linear inch of actual plotted output. Thus, if your plot is 46 inches long (not the paper, but the actual plot itself), then the cost is $5.60, or $1 setup plus 46 X 10 cents. We will refund costs for faulty output if the analyst believes that the error lies either in the machine or the documentation we provide.
You can have your poster plotted by coming to the ACC in person, identifying your plot in the queue, and asking then to plot it with whatever scale or expansion factor that you desire. You may also call the operators at 543-5933 to see if they can identify your plot in the queue and ask them to plot it, provided that you have a valid budget number or some other means of guaranteed payment.
While the resolution of the printer is 300 dots per inch, the maximum resolution that you should scan a document to be printed on the DesignJet is normally 150 dots per inch: any higher resolution is simply wasted and results in huge file sizes.
However, if your image is composed within an 8.5 x 11 inch page, and you have the operators at the I/O counter expand it by up to 419%, then you may scan it at up to 600 dots per inch, since the 600 dpi resolution is spread over 4 times the distance.
Large files result from a combination of physical size in inches and the dots-per-inch resolution for "raster" type images. The maximum file size that the plotter can handle is 64 megabytes, but in most packages it is ofen not easy to determine the file size. The exception to this is PhotoShop where the file size limits can be calculated before hand (see the section of this document on Photoshop which discusses file sizes and limits). However, you can determine the size of the PostScript print file from any package, and this has some bearing on the size that is acceptable to the plotter (in PhotoShop the PostScript print file may be about 2.5 times the 64 megabyte limit, but this relationship is not known for other packages). The safest thing is to print an initial version of your plot at a low resolution or size in order to verify its suitability for the plotter in other respects before attempting a very large file.
PhotoShop tends to produce the largest print files since it converts Postscript into a pixel map. Other packages, such as Freehand or PageMaker usually produce much smaller files unless pixel maps, such as from TIFF images, are a major part of the image.
Far and away the most difficult task in using the plotter is locating an image so that all of it actually shows up on the paper. This can be an extraordinarily trying procedure, unless you follow the steps outlined for each package below, because the results are not intuitive at all. Frequently only a small part of the image shows up, or you are left with a blank piece of paper with no obvious reason why.
The reasons for the difficulty include (a) the large number of graphics packages with different size, margin, and orientation controls and limits, (b) the limitations of different versions of the same packages, (c) the number of options which control plot size, paper size, margins, orientation, and scale factors, (d) different PPDs (Postscript Printer Description files) which control the characteristics of different printers and the sizes of allowable images, and (e) the scaling factors on the plotter itself.
You can deal with these difficulties by observing the following rules:
Note that this does not mean that the pathways given here are the only ones that will work. There may well be other combinations that are effective, but only the methods presented in this document have been tested and are supported by C&C.
The color that appears on paper almost never exactly matches the color you see on the screen, partly because the plotter uses a limited color palette, partly because color monitors need to be calibrated to certain specifications (and seldom are), and partly because the RGB --> CMYK (Red Green Blue to Cyan Magenta Yellow Black) conversion from screen to paper is never exact. CMYK colors often print better than RGB colors, but are about 33% larger in terms of file size.
Most packages let you specify either CMYK or RGB color output. The best approach is to create a color palette with many colors, print it, and compare the colors with what appears on your screen in order to get the colors you want.
Here are two color palettes that are available on-line: a Pan-Tone GIF palette and default PhotoShop color palette in JPEG format.
You may download these files from Netscape and read them into your package of choice in order to determine your own color needs.
The DesignJet printers can waste a great deal of paper by printing several blank feet after the plot is complete. In some packages you can explicitly control the size of the paper produced. Let us suppose that you want a plot that is 15 inches wide by 36 inches high. In Freehand 4 and Freehand 7 you can do this:
This approach does not seem to work in some other software packages, such as PhotoShop or PageMaker.
There are three main ways to send output to the plotters: from the two graphics Macintoshes that are located in the ACC building, from remote sites using the "prt" utility for letter size plots that are to be expanded by the plotter, and from remote sites using the "prt" utility for plots that are already at full size.
The graphics Macintoshes have the advantage of using the right PPDs and have rapid access to the plotter. You can either compose your image there, or you can compose it anywhere you like and load it on the ACC Macintoshes either by bringing in a diskette (PC or Macintosh), bringing in your ZIP cartridge for the drives that are installed on the Macs, or using FETCH to fetch it from somewhere on the internet (note that when you store an image on the internet, be sure and send it as a MacBinary II file if you are using a Macintosh so that the software can immediately recognize it by its icon).
The overall steps needed to print a file composed using packages such as PhotoShop, Freehand, PageMaker, PowerPoint, etc. are:
As noted before, you can also bring a ZIP cartridge and insert it in the ZIP dirve on the Machintoshes, or bring in a diskette if the file is small enough.
The main problem that may occur when printing from the PCs at the ACC is that the print command on the PCs may create a banner page which you cannot de-activate. Ask the operators at the I/O counter to be sure and check that the banner page is turned off (the operator can determine this by looking at an expanded view of the plot queue). If it is not turned off, your plot will fail.
If your plot is composed within the 8.5x11 inch letter size format, you can create your PostScript image file using the PRINT command in whatever package you use, and send it in ASCII mode to one of our Uniform Access computers, such as Saul or Homer. From there you direct it to the plotter with the "prt" command and request the operators at the ACC to expand your plot by one of the following 10 factors:
| 100% | 129% | 141% | 200% | 210% |
| 258% | 282% | 352% | 400% | 419% |
The steps needed to do this are:
| prt -q hp650c file.ps (for the HP650C plotter) or |
| prt -q hp755c file.ps (for the HP755C plotter) |
For more information on this route, see the section on "UNIX: Converting/Printing PostScript Files" below.
You may also compose and print full size files remotely using the "prt" utility and following the same steps as described in the above section "Printing Expanded 8.5x11 Inch Plots Remotely" with two exceptions:
On the Macintosh, you install these PPD files in the "Printer Descriptions" folder which is inside the "Extensions" folder which in turn resides inside the "Systems" folder.
The PPD files are needed for page sizes that exceed the standard 8.5x11 inch letter size. They are plain ascii text files that are currently available through anonymous "ftp" using the commands:
| ftp ftp.u.washington.edu |
| (login with the id of anonymous and your email as your password) |
| cd public/larryg |
| get hp650.ppd |
| get hp755.ppd |
| quit |
The software packages listed in the following sections have been tested with both of the DesignJet printers. Other packages, such as Canvas, may work equally well but we cannot offer support at the present time.
To select a large paper size for a PhotoShop image you:
If your file size (in Megabytes) is too large for the plotter, then you can reduce the resolution or the height and width within PhotoShop and then apply a scaling factor in the PAGE SETUP menu to compensate (the reason for this is that, in PhotoShop, the resolution and screen size of the image are linked together). To do this you:
This will exactly preserve the same physical size of the paper output but with a smaller file size and a lower level of detail.
We have successfully printed plots up to 35 x 100 inches from PhotoShop with margins of 1/2 inch on either side. Although we have not tested it, lengths up to 108 inches may be possible.
If you select PAPER to be LETTER size and compose your image to fit within an 8.5 x 11 inch page, then the margins are 1/4 inch left and right and about 7/10 inch top and bottom for the original image, yielding an actual image size of 8 x 9.6. When expanded by 419% this yields a plot 33.5 x 40.2 inches.
The size of a PhotoShop file is measured in three different ways:
The first and third sizes are completely independent of the complexity of the image and are determined by the following three parameters:
The IMAGE file size is approximately computed by the formula H*W*R*R*3 (for RGB images), or H*W*R*R*4 (for CMYK images), where the height and width are not the dimensions of the printed plot (the Color Plotter may expand the plot) but the size that is specified inside Photoshop. The Postscript print file is typically about 2.5 times the size of the PhotoShop IMAGE file. The IMAGE size, as opposed to the print file size, appears to set the limit for the HP plotter.
For example, a 7 x 10 inch plot with a resolution of 450 dpi is: 7*10*450*450*4 = 56,700,000 bytes, or nearly 57 megabytes. Since the maximum file size allowed by the plotter is 64 megabytes, this is close to the maximum size/resolution combination that you can print. However, the print file size is probably closer to 140 megabytes, but this should still be acceptable to the plotter.
The time it takes to rasterize and move a print file from the ACC Lab Macintosh to the color plotter is strictly proportional to the print file size as discussed above. It is approximately size-in-megabytes * 0.5 or about 2 megabytes per minute. So the huge 7*10*450*450 file mentioned above (whose print file size is about 140 megabytes) would take about 70 minutes to transfer to the plotter.
Note: at the present time the HP650 cannot handle Freehand files that contain embedded TIFF, GIF, or JPEG graphic files. Such files can be successfully sent to the HP755, however.
To select a larger paper size within Freehand, you:
You are normally limited to a size of 36 inches high by 54 inches long. However, there is a trick that lets you print pages nearly twice as long:
This will produce a plot that is 2N inches long. We have successfully tested a plot 36 x 108 inches long. Other scale factors, such as expanding a 12 x N plot by 300% may have unexpected results.
Note: at the present time the HP650 cannot handle Freehand files that contain embedded TIFF, GIF, or JPEG graphic files. Such files can be successfully sent to the HP755, however.
Freehand 7.x allows very long plots more easily that Freehand 4.x, but it requires one more step and some of the menus are different. To control the page size you:
Note that Freehand 7.x lets you get prints up to 108 inches long without having to use the "tricks" necessary in Freehand 4.x.
To select a large paper size in PageMaker on an ACC Macintosh you:
Note: while images can appear anywhere in an image, text appears to be limited to the first 21 inches. However, you can use the menu LAYOUT > COLUMN GUIDES ... to select 2 columns, in which case you can print text in a second column that starts at 21 inches and extends to 42 inches. However, these columns are independent and you cannot have text that spans the two columns and still retain perfect alignment. Nor can you usually place graphics that span the two columns.
There is a trick you can use to get pages up to 36 x 64 inches long in PageMaker. In the DOCUMENT SETUP menu, key in values where the length of the plot is less than or equal to the maximum value of 42 inches, as specified in the DIMENSIONS menu item. Later, when you enter the PRINT menu, select not only the correct PAPER size but also set the SCALE factor to expand the plot to the desired size. However, while this permits plots greater than 42 inches in lenght, the resulting plot is often shorter than you would expect from its scaling factor. The following table shows the results of applying scale factors in the PRINT menu:
| DIMENSIONS | Margins | Scale Factor | Paper Size | Computed Plot Size | Actual Plot Size |
| 16 x 8 inches | 0.5 | 200% | 36 x 60 | 29.7 | 29.5 |
| 16 x 8 inches | 0.5 | 300% | 36 x 60 | 44.6 | 43.6 |
| 16 x 8 inches | 0.5 | 400% | 36 x 72 | 59.5 | 50.6 |
| 16 x 8 inches | 0.5 | 500% | 36 x 84 | 74.4 | 57.6 |
| 20 x 12 | 0.5 | 300% | 36 x 72 | 57 | 56 |
| 42 x 18 inches | 0.5 | 200% | 36 x 84 | 82 | 64 |
The shortfall is always on the right side of the plot, so if you allow enough blank space on the right side of your plot you will be safe. In many cases, the shortfall is less than an inch, but in some cases, such as 42 x 18 inches expanded by 200%, the rightmost 9 inches of your PageMaker plot must be blank so that when the plot is expanded by 200% the rightmost 18 inches occupy the blank part of your plot.
To select a large paper size in PowerPoint on an ACC Macintosh:
Note that PowerPoint is sometimes used to create large size plots from other graphics packages. See the description of Microsoft WORD below for an explanation. Also note that PowerPoint can be used on any ACC Macintosh and not just the ones reserved for graphics.
If you compose a WORD document within the standard 8.5 x 11 inch format, you may either send it directly to the plotter using the Macintoshes at the ACC building, or print it to a file in PostScript, transfer it to a Uniform Accesses machine, and use the "prt" command as explained earlier. For both these cases, you normally ask the operators to use the scale factor on the plotter to expand the picture by up to 419%.
On the other hand, if you wish to control your page size within WORD itself, you are faced with a serious limitation: the page size of Microsoft WORD files is limited to 21 by 21 inches. The obvious solution might be to design it close to those limits and have the plotter scale it by some factor, e.g., compose a 12 x 20 inch plot and ask the operators to scale it by, say, 300%. However, that will likely result in a blank sheet of paper because you cannot expand plots that are not in letter size (8.5x11 inch) format. An approach that will work is to incorporate the WORD document in another package, such as PowerPoint, and then use the mouse to expand it to the maximum that PowerPoint allows. The steps needed are:
Also note that WORD can be used on any ACC Macintosh and not just the ones reserved for graphics.
To select a large page size in Framemaker you:
| /FMAllowPaperSizeMismatch | false def |
| Use an editor to change the "false" to "true", i.e., | |
| /FMAllowPaperSizeMismatch | true def |
and then save the edited file.
| prt -q hp650c file.ps | or |
| prt -q hp755c file.ps |
You print Postscript files to the HP DesignJet printer with the command:
| prt -q hp650c file.ps | or |
| prt -q hp755c file.ps |
where "file.ps" is the name of your Postscript file. If your file is internally scaled smaller than you wish (for example, many Postscript files are scaled to fit within 8.5 x 11 inches), you may ask the operators at the I/O lobby to expand it by one of the 10 scale factors listed above.
You may also print enlarged GIF files on the HP DesignJet printer by converting them to Postscript format using the utilities "giftopnm" and "pnmtops" contained in the NETPBM suite, plus a filter program named "ps2hp" which corrects (and optionally scales) the output from pnmtops for the HP plotter. The commands are:
| set path=( /usr/local/netpbm $path) |
| giftopnm < my.gif | pnmtops | ps2hp | prt -q hp650c |
The program ps2hp has optional parameters which let you scale the hardcopy output. Its full syntax is:
| ... | ps2hp [-s scale] [-x xscale] [-y yscale] | ... |
where "scale", "xscale", and "yscale" are optional numbers between 0.0 and 10.0. For example, to enlarge a GIF file named "top.gif" by 20%, in both the x and y directions, you type:
| set path=( /usr/local/netpbm $path) |
| giftopnm < top.gif | pnmtops | ps2hp -s 1.2 | prt -q hp650c |
Note that the "set path=( /usr/local/netpbm $path)" statement need only be executed once per terminal session.
Many other file types, such as JPG, PPM, TIFF, X11 bitmap, Sun Rasterfile, RLE, RGB, BMP, PCX, PM, and a few others can be converted to PostScript using an Xwindows program named "xv" in conjunction with the "ps2hp" program. xv also lets you modify the image in terms of color, dithering, or orientation. You must use xv on an Xterminal or equivalent. Let "file.xxx", where "xxx" is a graphic file suffix such as "gif" or "tiff", be a graphics file. You convert and plot it as follows:
If you must change the size of an existing Postscript file by other than the 10 scale factors listed above, or if your particular Postscript file is not accepted by the HP plotter, or if you just need to convert a Postscript file to another format (for example, to convert it to "gif" format so as to use it on the WWW) then you can convert it to an intermediate format which can be scaled to any desired size or converted to another graphics format. Be aware that this approach (a) may use a lot of disk space so that you may have to use the "chkout" utility, and (b) may result in a substantial loss of resolution, especially when going to a printer as opposed to a display screen.
The programs to do this are located in "/usr/local/netpbm" and are named "pstopnm", "pnmtops", and "ppmtoxxx", where "xxx" is a graphics file postfix.
For example, to convert a Postscript file to "gif" format you type:
| set path= ( /usr/local/netpbm $path) |
| pstopnm -xsize 600 -ysize 800 file.ps |
| ppmtogif < file001.ppm > file.gif |
where -xsize and -ysize specify the number of pixels in the x and y dimensions and may range from 50 to 6000.
To scale a Postscript file by other than the 10 standard scale factors you could do this:
| set path= ( /usr/local/netpbm $path) |
| pstopnm -xsize 700 -ysize 1000 file.ps |
| pnmtops file001.ppm | ps2hp -s 1.28 | prt -q hp650c |
which creates a Postscript file with a resolution of 700 by 1000 (as well as an aspect ratio of 7-to-10) and then scales it by a factor of 1.28 when it sends it to the HP DesignJet printer.
Since the HP DesignJet costs money, you may wish to preview your graphics before sending it off for final printing. If your Postscript file is within an 8.5 by 11 inch page, you may preview it on an Xterminal using the utilities "gs" or "ghostview". For example, you can convert "earth.gif" to Postscript and preview it on Saul with the commands:
| saul% set path= (/usr/local/netpbm $path) |
| saul% giftopnm < earth.gif | pnmtops | ps2hp > earth.ps |
| saul% gs earth.ps |
See if it looks OK on the screen, and type "quit" to get out of "gs". You can also print a free monochrome copy on the xerox printer with the command: "prt -q xerox -code postscript earth.ps"
Send the Postscript file "bchart.ps" to the color plotter:
| prt -q hp650c bchart.ps |
Send the GIF file "earth.gif" to the DesignJet and expand it by 30%:
| set path=( /usr/local/netpbm $path) |
| giftopnm < earth.gif | pnmtops | ps2hp -s 1.3 | prt -q hp650c |
Send the JPG file "mars.jpg" to the Designjet and expand the x dimension by 50% and the y dimension by 100%:
| xv mars.jpg |
| ps2hp -x 1.5 -y 2.0 mars.ps | prt -q hp650c |
