Printing Computer Modern

[huusa]

In a PDF document printed using PDF-XChange Viewer (version 2.5), Computer Modern fonts seem to be heavier than when printed using Adobe Reader. To illustrate this, I have scanned a page which I printed with Adobe Reader and PDF-XChange Viewer. I took snapshots of the word number in the scanned PDF. The scan and snapshot were taken at 600 DPI. When the snapshots are viewed sequentially, it is immediately obvious to even the most casual observer that the version printed with PDF-XChange Viewer is heavier. Even though page scaling settings may have slightly affected the size of the fonts, I suspect that there are differences between PDF-XChange Viewer and Adobe Reader in the way in which they rasterize fonts. There is also a sample PDF file created using mostly the same software as the PDF from which the PNG files were taken. I recently bought a book from Springer and noticed that font weight varies noticeably from line to line. That book was also typeset with Computer Modern. I found that variation rather distracting.

My problem is that I do not like the heavy version of Computer Modern. This problem is of course easy to work around because I can print with Adobe Reader, but I would like to hear whether others have had similar problems. Can Tracker give a definitive explanation for the difference between Adobe Reader and PDF-XChange Viewer?

[Paul - PDF-XChange]

Hi huusa,

thanks for the post and samples. I printed this to a Brother laser printer and I cannot see a difference in the printed output on here. It may be that the printing variation is specific to the way each of the programs is communicating with your physical printer.

Do you have access to another printer to test this on? If it is specific to the printer then I would suggest that there may be little we can do in the current 2.5 series of the Viewer as development effort is currently squarely focused on finalizing version 3 for it's March release.

Something that comes to mind that could throw some light on the issue include the type of driver used, is it native to the printer manufacturer or perhaps PostScript or PCL? We are improving our PS and PCL printing in V3 and if this is the case then you might need to wait for V3 to see a change.

Also, it is always important to make sure you are using both the latest build of PDF-XChange. Use Help --> Check for Updates to get build 207 (current) as well as having the latest drivers from your printer manufacturer.

If there are alternative drivers it may be helpful to switch from what you are using to one of the others (not PCL or PostScript if available).

hth

[huusa]

The first samples were printed using Konica Minolta Bizhub B451 and its drivers via a print server. I no longer have access to that printer because it has been decommissioned but I made new ones with Canon iR-ADV C5250/5255 UFR II and its driver. The new samples also show differences between PDF-XChange Viewer and Adobe Reader. This time PDF-XChange Viewer's output seems to be more aesthetically pleasing. There are no longer distinctive differences between stroke weights but instead serifs and fillets differ.

Does this mean that the reader software renders fonts and sends them to the printer driver? Because if the printer or its driver rendered fonts, should not they then be identical on paper?

[Stefan - PDF-XChange]

Hello huusa,

Our current Viewer will convert all fonts that are embedded in a PDF to curves and then send them to the printer for output on paper, and based on how the printer handles curves vs actual fonts this could cause more noticeable difference on some printers. As Paul mentioned there would be little if any change to the printing routines in the current Viewer, but once the printing in V3 is complete - it should offer much more precise printout of the actual fonts used.

For the time being please try "print as images", use sufficiently high DPI for images output and make sure that your printer is not e.g. trying to save ink/toner when printing images and you should get on paper exactly the font you see on screen.

Best,
Stefan

[Ivan - Tracker Software]

Adobe Acrobat/Reader often renders fonts (mostly Type1, but the exact logic is unknown to me) and sends them to the printer driver as images.