Print quality in Altium vs PDF viewer - Page 1
Forum section: electronics / general

author: qat
author_rank: Contributor
timestamp: February 03, 2022, 08:47:07 pm
content: I noticed today that if you ctrl+P in Altium to print anything the quality ends up being really bad compared to outputting it as a PDF and then printing.Sometimes I ctrl+P and then print to PDF to save on your computer whenever I need a quick image of whatever and I've always thought the quality is really bad. Now I know why... Hopefully this can help someone else too.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 03, 2022, 09:03:16 pm
content: Huh, not sure how much of that is due to your printer versus how the document is formatted; I've not noticed that stripey pattern before, but I'm guessing that's specific to the color laser printer or whatever it is you have, moreso than the document?Is interesting that, it seems like the DPI itself is varying between formats. Maybe the print dialog is set differently too? (See any "draft" or DPI/resolution settings in there?) Maybe the printer "knows" and just doesn't bother for the one?Have noticed sometimes my printer gives low resolution on later pages, I think because the spooler accidentally runs out of buffer size or something. That's probably specific to my computer or printer though, and it's not consistent (i.e., I print off say 10 pages and the last few are blurry, I re-print the last pages individually and they're fine; like I said, spooler memory or something).I don't know how Altium formats documents those ways (load it up on a PDF object editor to find out?), but yeah they are different, it's a different method than Smart PDF/Output Job. The latter is richer and more consistent/portable (portable in the sense of copying the OutJob to other projects and so on; well, in some things like SCH outputs, but not others like PCB layers you need to customize for whatever layers the PCB uses, if different), so I would recommend using it.Tim

author: qat
author_rank: Contributor
timestamp: February 03, 2022, 10:48:51 pm
content: Quote from: T3sl4co1l on February 03, 2022, 09:03:16 pmThe striped pattern is the printer's way of rendering a light blue color. With the naked eye its not visible, the image in my post is high magnification. In the print directly from Altium the blue is a lot darker which the image doesn't show that well. Both are printed on the same colour laser printer.I've looked through all the settings - Page Setup > Printer Setup > Properties > Paper/Quality > Advanced - without any DPI options. It seems like whenever you print directly from Altium you get a compressed shitty version of whatever it is you're working on. See attached.

author: free_electron
author_rank: Super Contributor
timestamp: February 04, 2022, 03:05:21 am
content: ctrl-p rasterizes using a generic windows print spooler.if you send to pdf you are actually writing vector graphics ( open the pdf in illustrator or inkscape and you can explode the drawings into vectors.when printing the pdf adobe could be sending vector data (postscript or PCL) to the printer so the printer does the rasterisation.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: February 04, 2022, 06:03:22 am
content: There are some odd bugs in AD PDF output (through an Outjob). Depending on the PDF version selected, they use different rendering engines, each with a different set of bugs. With either default or v1.4 selected, no fonts are embedded in the PDF, so it looks awful if you view it on a machine without those fonts installed. The rendering engine is "llPDFLib 3.x". With PDF versions 1.5 through 1.7, the fonts are embedded, but with the wrong name (spaces get stripped out), so they still don't look right. The engine used in this case is "3-Heights(TM) PDF to PDF-A Converter". I use Courier New Bold, and the embedded font is named "CourierNewBold", what's actually shown is plain Courier New without the bold attribute. If the document contains an embedded vector graphic, the PDF output includes a bitmap image of just that part of the page. Until recently, that image was super low resolution, but at least now it's at ~300 dpi.

author: qat
author_rank: Contributor
timestamp: February 04, 2022, 02:00:08 pm
content: Quote from: radar_macgyver on February 04, 2022, 06:03:22 amThis is very interesting.I have had huge problems with fonts. I only switched from KiCad to Altium in version 18, and I tried to use a proprietary font which caused a lot of issues; I ended up sticking with Times New Roman. Only recently in Altium 21, I decided to try again and updated everything to use a different font, but some odd issues still persist when exporting to PDF. For me everything looks fine while other people have my font switched to Arial, which also looks fine but not as intended.Do you know how recently they upped the resolution? I’ve had problems with resolution in the past but a year or so ago it appears to have to fixed itself. Maybe it was some kind of update or I found the right setting to fix it.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: February 05, 2022, 06:44:31 am
content: I don't know the exact revision, but it was about 3 months ago that the embedded images started having a higher resolution. There are lots of BugCrunch reports filed about this, and I voted on some, so I was notified when they changed the reports to 'solved'.The Arial default is what happens when I open PDFs with Atril under Linux. On Windows, I use SumatraPDF, which shows things in the expected font (Courier New bold, in my case). With Acrobat Reader, there's an option to use local fonts under Edit>Preferences>Page Display>"Use Local Fonts". Turning this off shows the document with Arial substituted everywhere. This is true when you set the PDF output version to 1.4. With versions set to 1.5 or greater, Atril, SumatraPDF and Adobe all show the wrong font (Courier New, without bold), regardless of settings.Another regression in PDF output on AD >= 18: components used to display a popup menu when clicked. I had set up a documentation link in my libraries that linked to the datasheet that you could access from this menu. Newer versions of AD don't output PDFs that have this feature. While I appreciate that the rewrite of AD solves the old out of memory issues, so many other things broke in frustrating ways, and the company doesn't seem to care.

author: PlainName
author_rank: Super Contributor
timestamp: February 05, 2022, 05:44:47 pm
content: QuoteAD21 certainly does that. The PDF viewer needs scripting enabled so I wonder if you've accidentally disabled it on your viewer (or not enabled if a newer viewer).

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: February 12, 2022, 08:02:24 pm
content: Quote from: dunkemhigh on February 05, 2022, 05:44:47 pmOnly if you set the PDF output version to 1.4, and only with Adobe Reader, though this is a limitation of other readers and not AD. With higher versions (the only ones that embed fonts correctly), clicking on components highlights them, but I don't get a popup menu. I believe this is because AD internally passes the PDF through the "3-Heights(TM) PDF to PDF-A Converter", which strips out the scripting needed to show the popup menu.

author: PlainName
author_rank: Super Contributor
timestamp: February 12, 2022, 08:52:31 pm
content: Yeah, it's pdf 1.4 but I use pdfXchange - won't have any Adobe stuff on my PCEdit: added screeny of popup

author: exmadscientist
author_rank: Frequent Contributor
timestamp: February 13, 2022, 09:50:21 pm
content: Quote from: free_electron on February 04, 2022, 03:05:21 amIt's worse than that. The "stripey" colored areas are often characteristic of Brother color lasers. Brother drivers are very fond of JPEG mode, where they actuallysend a JPEG-compressed rasterto the printer. This looks about as nice as it sounds like it does. It can be real work to get a Brother printer accepting PS/PCL/whatever. (Starting point for success: install the driver yourself instead of through Windows.) So I'm guessing one of OP's output paths is triggering JPEG-driver mode and one isn't.Oh, and all the other BS in this thread is real. Altium, the worst piece of crap out there... except for everything else