OpenStreetMap

Adding a Preview JPG + crop-marks for printing

Posted by alexkemp on 5 February 2019 in English (English)

This is a another small update to a sequence of posts on updating some small leaflets originally produced by Andy Allan:–

  1. Fonts missing from OSM Promotional Leaflets
  2. Github HowTo: Clone Repository then make a Pull Request
  3. Printing OSM Promotional Leaflets
  4. Update to OSM Promotional Leaflets due to Padding errors
  5. Adding a Preview JPG + crop-marks for printing

OSM leaflet preview

This is how to add crop-marks and bleed-marks to a production-PDF for printing (the PDFs within GitHub do NOT currently contain any crop-marks and, whilst they contain 3mm bleed, they do NOT contain bleed marks either):–

  1. Load your production-ready SVG into Inkscape
    (see earlier pages for links if you need to install)
  2. Under r15371 (the most recent) go Extensions | Render | Layout | Printing Marks…
  3. Put ticks in Marks | Crop Marks + Marks | Bleed Marks
  4. On Positioning tab set:

      Set crop marks = `Canvas`
      Set       unit = `mm`
      Set     offset = `0.000`
      Bleed Margin
              Top    = `3.000`
              Bottom = `3.000`
              Left   = `3.000`
              Right  = `3.000`    
    
  5. Click ✔Apply (and wait a little while it works)

You will see that both options in the JPEG above contain both sets of marks; that is really quick & easy to produce.

This was a temporary edit as I was simply producing two PNGs for a preview image of the 2 options for the leaflet front (the printers had asked for 3mm bleed but NOT for crop-marks). As a final visual guide I added 3 x vertical dotted-lines to show where the leaftet is folded. The next step is to export the finished product as a PNG file.

Exporting is easy, but the range of options is a little terrifying. Fortunately the defaults worked:

  1. Select File | Export PNG Image…
    (a dialog appears)
  2. Select Drawing as Export area (after checking that dimensions are correct under Page)

After setting a name (I left the default of name.svg.png) all the other defaults proved to be correct. That was NOT a coincidence. I had previously taken every precaution to make the page-size accurate, then apply (internal) 4mm padding + make (external) 3mm margin available (which is the bleed, set when the PDF is produced, although more than that actually exists). Thus, the defaults were all setup accurately.

Finally, push ✔Export and check the result (there is zero confirmation from Inkscape).

I used GIMP to put the two PNGs together and exported as a JPEG. The GIMP master file has been uploaded to try to make it easy for anyone that wants to make changes. The whole thing has been pushed to GitHub as a further commit. I hope that some will find it useful.

Good luck!

PS
This looks like a good link if considering PDFs & crop-marks (the summary is: “PDFs are best for printers, use crop-marks but no others, use 300dpi for raster items”). It also said “Acrobat Reader is the best application to use when opening and viewing a PDF file.”. I almost spat tea all over my monitor when I read that. It points out that printers will probably get in a huff if you include colour registrations, etc. (I thought that they looked splendid, but would not be included in the PDF in any case since they are located outside of the bleed).

Modern SVGs use 96dpi. The ones used by Inkscape r9886 (the latest version available when Andy first designed these leaflets) used 90 dpi. That change from 90dpi to 96dpi caused hours & hours of re-formatting when I updated the whole GitHub package from r9886 to the current r15371.

It makes sense when printing to go down in resolution if needed for some reason, but you cannot go up in resolution and then see any actual difference in the end product. That means that, if the PDF is going to contain any raster images (and PNG are raster images), then the SVG source files will need to reference 300dpi images to get a 300dpi end product.

To try to get a measure of the problem:

$ identify globe_part_halo.png london.png    
globe_part_halo.png PNG 3208x3880 3208x3880+0+0 8-bit sRGB 8.236MB 0.000u 0:00.000
london.png PNG 2479x1356 2479x1356+0+0 8-bit sRGB 2.119MB 0.000u 0:00.000

pixelto conversions at 96dpi + 300dpi
(leaflet pages are 73mm wide x 105mm high):

pixels    96dpi  300dpi
------  -------  ------
 3,880  1,027mm   329mm
 2,479    656mm   210mm

It looks like it should be possible to use the current source files to print at 300dpi but I am unsure of the methodology to get from the current SVG dpi to PDF dpi. Advice appreciated.

Location: Thorneywood, Sneinton, City of Nottingham, East Midlands, England, NG3 2PB, United Kingdom

Comment from Rovastar on 6 February 2019 at 02:28

Did you not update the image used?

That image of London is old nd has missing buildings, etc.

It is probably a few years out of date. Osm probably has had double the map data (nodes, ways, etc) since then.

Here is what it looks like now.

https://www.openstreetmap.org/#map=15/51.5077/-0.1298

I never liked original image as most of central London has been well mapped for years and they choose an area showing St. James/Mayfair that no-one had mapped. An odd choice as IMHO we should be showing the best most complete type of areas to show off osm

Comment from alexkemp on 6 February 2019 at 10:34

Hi @Rovastar

Did you not update the image used?

Well, so far I’ve had to learn about SVG1.1, SVG1.2, SVG2.0, Inkscape, GitHub & git, Bleed & crop-marks, printing from PDFs, pdfunite, unix2dos - and all without a scap of formal education in these things. Somehow I found myself avoiding updating any of the source PNGs for the leaflets during that process. And yes, it is more than a few years out of date.

I would be most happy to accept donations from anybody of replacements/alternatives for any of the PNGs, but particularly:

globe_part_halo.png (front cover)
london.png (inside 2-pages)

For my own situation (I live in Nottingham) I thought that a map of the heart of Nottingham would be suitable to replace london.png, and I’m quite certain that Americans, Australians, etc. want something less Eurocentric for the front-cover & middle. I would be most happy to accept pushes with PNGs of other places. The SVG is set for 96dpi.

For the alternate (osmflyer1-2) I’ve placed the London map under a mask, so any PNG that you provide could be a more generous size. I have thought that it would be best to bleed it off at top & bottom & did not only because I was concerned that the resolution might then be too low.

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