PLP Digital Systems - Tips and Tricks

Tips and Tricks: Multi-page PDF File Expansion

PLP Digital Systems — Mon, 13 Feb 2012 14:00:00 +0000

Our Customer Support team receives several calls and emails every month related to multi-page PDF files that do not expand to show their component pages when added to a new job. These are some of the most common causes...

The PDF File is a Portfolio/Package

When someone combines multiple files with Adobe Acrobat, they are given the option of creating either a multi-page PDF file, or a PDF Portfolio/Package. Newer versions of Acrobat use the term "Portfolio," while order versions use the term "Package." A more generic term for either is "Binder."

A PDF Portfolio/Package is, in many ways, similar to a zip file. It may contain PDF files (either single- or multi-page), PNG images, TIFF images, JPEG images, Microsoft Office documents, and even other PDF Portfolio/Package files. Due to the indeterminate nature of the content, PlotWorks can not expand a PDF Portfolio/Package to show its content. When added to a job and viewed or processed, a warning will indicate that the file is a PDF Portfolio/Package.

To determine if a PDF file is a Portfolio/Package:

Open the file with Acrobat (Reader, Standard or Pro)
If each image is shown with a filename (including the .pdf extension), the containing file is a PDF Portfolio/Package.

To avoid this issue, please share this list of PDF Creation Tips with your customers.

The PDF File has been Secured to Prevent Page Extraction

When creating a PDF file with Acrobat, you may elect to secure the file via one or more methods:

Encryption
Require a password to open the document
Require a password to bypass editing and printing restrictions

If the security settings prevent page extraction, PlotWorks will not be able to expand the file to show its component pages when adding the PDF file to a job.

To examine the security settings for a PDF file:

Open the file with Acrobat (Reader, Standard or Pro)
Choose Properties from the File menu (or use the Ctrl + D shortcut)
Go to the Security tab

To avoid this issue, please share this list of PDF Creation Tips with your customers.

The PDF File Consists Largely of ANSI A or A4 Documents

PlotWorks version 7.0 introduced a distinction between Office and Technical documents. By default, a multi-page PDF file that consists largely of ANSI A (8.5 x 11 inches) or A4 (210 x 297 mm) pages will be classified as an Office document, and the file will not be expanded to show its component pages when added to a new job.

This feature was added to support remote submissions from either the PlotWorks Remote Client or eOrder where the submission includes both plans and specifications. If a user were to submit a 40 page PDF file consisting of plans, the document will be classified as Technical and expanded to show its component pages. If the same submission contained a 200 page PDF file consisting of specifications, the document will be classified as Office and will not be expanded.

If you open the job for viewing, you may change the classification from Office to Technical by using the List View Layout. When you change the classification, the ANSI A or A4 document will be expanded.

If the default behavior is undesirable in your workflow, please contact Customer Support for assistance with disabling or modifying the triggers for this feature.

PlotWorks may not be Detecting Pages Properly

If you encounter a PDF file does not expand as expected please contact Customer Support for assistance. PlotWorks may not be properly detecting the pages. Although this type of error is infrequent, it is not unexpected given the thousands of PDF variants that we support.

Tips and Tricks: PDF Creation Tips

PLP Digital Systems — Wed, 02 Nov 2011 13:00:00 +0000

Software vendors such as Adobe, Autodesk and Bentley have made PDF creation fairly simple for document creators: one or two mouse clicks using the default settings. However, the default settings used during PDF creation may not produce an optimal, print-ready file.

Over the years we've handled thousands of customer support inquiries related to conversion or printing of problematic PDF files. Many of these problem files have similar characteristics.

Document creators should keep the following guidelines in mind when producing PDF files:

Always embed all fonts -- no exceptions. A PDF file without all fonts embedded is not a print-ready file.
Do not password-protect your files.
When encapsulating multiple single-page PDF files into a single PDF file, make sure you create a multi-page PDF file, not a Portfolio or Package.
Be careful in your use of grayscales when printing to a monochrome printer. Light lines and text (example: 15% gray) may be difficult to see or read.
Be careful in your use of color when printing to a monochrome printer. Light lines and text (example: yellow) may be difficult to see or read.
Disable line merge whenever feasible. This will greatly decrease processing overhead, and will generally have little visual effect when printing to a monochrome printer.
Do not rely on free or inexpensive PDF tools without adequate testing. The results may or may not conform to the PDF specification.

Tips and Tricks: Recommended Pen Macros

PLP Digital Systems — Thu, 27 Oct 2011 12:16:18 +0000

When using PlotWorks with a monochrome printer, the pen macro specified for each image in the job will affect the characteristics of the images produced. The pen macro (more properly described as a processing macro) can be used to control many imaging parameters, including dithering method (how colors and grayscales are converted to monochrome).

Note: the information below assumes that the default dithering type in the PlotWorks Printer Interface (Setup > Advanced Options) is set to Ordered plus High-Resolution Patterns on all three tabs: Vector Imaging, Raster Imaging, Polygon Fill Imaging.

Summary

Macro Combination	Recommended Usage
WPM	Reasonable default for all file formats. This tends to provide the best results for dark lines, dark text, area fills and embedded images. Light lines and light text will appear dotted (sometimes described as "pixelated"). This macro dithers colors and grayscales using high-resolution ordered patterns.
WPMR	Also a reasonable default for all file formats (depends on user/customer preference). This usually provides inferior results for area fills and embedded images, but for lines and text it provides better results than WPM. This macro dithers colors and grayscales using error diffusion.
WPMAB	This is not a reasonable default for any file format, but it can be used to handle certain problem files. This will flatten all colors and grayscales to black. An example of where this comes in handy: a customer sends you a file where all of the text is yellow. Regardless of whether you use high-resolution ordered patterns (WPM) or error diffusion (WPMR), the text is almost impossible to read. With WPMAB, all non-white pixels are mapped to black.

Explanation

At a minimum, the pen macro should be WPM.

Macro	Description
W	Honor the pen widths as defined within an HP-GL/2 file. This macro is ignored when processing anything other than an HP-GL/2 file.
P	Honor the pen colors, fills, strokes, transparencies, and line ends as defined within an HP-GL/2 file. This macro is ignored when processing anything other than an HP-GL/2 file.
M	Process the file in color (multi-plane). With PDF files, if the M macro is not present, the PDF interpreter (our tailored version of Ghostscript) will dither the file. With PDF files, if the M macro is present, the PDF interpreter will return a color file which is then dithered by PlotWorks using either high-resolution ordered patterns or error diffusion. Most customers prefer to let PlotWorks perform the dithering to obtain optimal image quality.

With WPM, the default dithering method is to map colors and grayscales to one of 256 high-resolution ordered patterns. Each pattern is a 16x16 grid of pixels (256 pixels total). Each pixel maps to the pixel space on the printer (400 or 600 pixels per inch, depending on printer make/model). In pattern 0, all 256 pixels are white. In pattern 255, all 256 pixels are black. To further illustrate an example of pattern application, a 20% gray value (RGB 204, 204, 204) will be mapped to pattern 51 (20% x 255 = 51), which looks like this:

If a 20% gray line is dithered with high-resolution ordered patterns, the resulting line in the monochrome TIFF or PDF file appears dotted.

As noted above, high-resolution ordered patterns tend to provide the best results for dark lines, dark text, area fills and embedded images. Light lines and light text will appear dotted (sometimes described as "pixelated").

Macro	Description
R	Use error diffusion to dither colors and grayscales. Error diffusion uses a random placement of pixels to represent colors and grayscales. Darker values are represented by increasing the density, while lighter values are represented by decreasing the density. As noted in the summary above, this usually provides inferior results for area fills and embedded images, but for lines and text it provides better results than high-resolution ordered patterns.
AB	Flatten all non-white drawing entities to black. Use with caution!

Macro

Description

Use error diffusion to dither colors and grayscales. Error diffusion uses a random placement of pixels to represent colors and grayscales. Darker values are represented by increasing the density, while lighter values are represented by decreasing the density. As noted in the summary above, this usually provides inferior results for area fills and embedded images, but for lines and text it provides better results than high-resolution ordered patterns.

Flatten all non-white drawing entities to black. Use with caution!

Exception

If you are printing full size monochrome TIFF images at a scale factor other than 100% (either an enlargement or a reduction), you should change the macro to just the tilde (~) character. This will invoke a unique resampling algorithm which will retain grayscales and detail. You can learn more about resampling here.

Tips and Tricks: Resampling

PLP Digital Systems — Sat, 23 Apr 2011 06:13:02 +0000

To obtain optimal quality when scaling monochrome (black and white) TIFF images, use resampling. This is applicable whether you are printing or converting (Output to File).

Here's a common scenario:

You receive a full size-set of originals. The title page has a large image: an architectural rendering of the project.
You scan the originals to create full-size monochrome Group IV TIFF images.
You print a full-size set and it looks fine.
You print a half-size set and the rendering on the title page is dark, and it is difficult to discern detail.

When you produce a half-size image from a full-size original, the resulting image occupies only 25 percent of the original area. To look at it another way, three out of every four pixels must be discarded. Without resampling, the tendency is to retain black to avoid loss of content. This is why renderings tend to get very dark when printing half-size drawings from full-size monochrome TIFF images.

When you invoke resampling while scaling, your PlotWorks software will:

Divide the original image into very small subsections
Convert each subsection to its grayscale equivalent
Scale the grayscale image
Dither the scaled grayscale image to monochrome when printing to a monochrome device.

Resampling is invoked during preflight by using the tilde (~) character in the Job Editor's Pen Macro column. If you can't remember the tilde character, you can always use the Pen/Print Options tab on the Job Editor's Detail Property Sheet. This option is listed under Rendering Options > Advanced > Resample All Monochrome TIFF.

It is important to remember that resampling is only applicable to monochrome TIFF images, and only if the scale factor is not 100 percent.

When working with vector images PlotWorks always scales prior to rasterization, eliminating the need to resample images. Half-sizes from vector images can still be challenging, but resampling is not required.

If you use resampling frequently, it might make sense to create a job template:

Create a new, empty job in the Job Editor
Highlight the "Proto" line
Change the Pen Macro to ~
Save the job as "Template Resample Monochrome TIFF.PLP"
Right-click on the .PLP file that you just saved, choose properties, and set to "Read Only"

More information about resampling, including sample images, is available here.

Tips and Tricks: 2-Up Printing

PLP Digital Systems — Mon, 04 Apr 2011 09:02:30 +0000

PlotWorks supports nesting or tiling of two or more images on each sheet. The following solution describes, as an example, how to print 10 sets of 30 images that are each 30 inches x 42 inches at 50% scale and nested 2-up on 30 inch bond.

Add all 30 files to the Job Editor
Change the Scale of the images
1. Select the first file in the list
2. Click on Properties and select the Output tab
3. In the Scale By dropdown select Percentage
4. Change the Scale to 50%
5. Click Specify Final Media Size
6. If your documents are landscape set the Final Width to 21 inches and set the Final Height to 15 inches
7. If your documents are portrait set the Final Width to 15 inches and set the Final Height to 21 inches
8. Click on the Output field for the first file so activate this field
9. Select Edit > Copy Field Down to apply the Output Size and Scale to all images in the set. The keyboard shortcut CTRL + I may also be used.
Change the copy count for the images in the job to 2
1. Select the first file in the list
2. Change the quantity field (Qty) to 2
3. Select Edit > Copy Field Down to apply the quantity to all images in the set. The keyboard shortcut CTRL + I may also be used.
Enable nesting
1. Select Setup >Preferences then select the Nesting Options tab
2. Enable Nesting and set Maximum images to nest to 2
3. Set the Border between nested images to 0 then press OK
Print the sets by using the following steps:
1. Click Output
2. Change the number of Sets to 5 then press OK

Always set the quantity column to the number of images that need to be nested. Set the quantity to 2 for 2-up printing, and set the quantity to 4 for 4 up printing.

Set the number of sets to the total number required divided by the number of images nested.

PLP Digital Systems - Tips and Tricks

Tips and Tricks: Multi-page PDF File Expansion

The PDF File is a Portfolio/Package

The PDF File has been Secured to Prevent Page Extraction

The PDF File Consists Largely of ANSI A or A4 Documents

PlotWorks may not be Detecting Pages Properly

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Tips and Tricks: PDF Creation Tips

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Tips and Tricks: Recommended Pen Macros

Summary

Explanation

Exception

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Tips and Tricks: Resampling

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Tips and Tricks: 2-Up Printing

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