Magic letterhead tray – making preprinted stationary automatically on plain white paper

A couple of years ago I stopped buying letterheads for my business and instead created a special print queue that merged any document sent to print with a PDF letterhead template.

Last month, it stopped working on just my PC. I’m not quite sure if it broke from a Windows update or something else had changed but the result was I needed to start from scratch and make it all again. My original notes weren’t very good and in 3 years time I’ll look back on these notes and think much the same. If you’re looking to print letterheads on demand too, these notes may help you achieve it.

Getting here took me far to long (days!) but the end result is not having to buy preprinted stationary or an extra tray for our printer.

Summary of what I’m about to do:

• Create a Print Server (a virtual machine) running linux (Ubuntu) and CUPS (common unix printing system)
• Connect the Print server to the network printer
• Create a queue for the printer and share that queue to the network.
• Within that queue, call a script that turns the print document into a PDF, merge that with a pre created ‘letterhead’ PDF
• Send that newly merged document to the printer.

Things that are good to know: Issues and solutions:

• Sometimes windows doesn’t like browsing for printers, giving error .“Couldn’t connect to printer. Check the printer name and try again. If this is a network printer, make sure that the printer is turned on and that the printer address is correct”
  Solution was to open ‘services’ and restart ‘Print spooler’ service
• I also found using “http:” for printer connections rather than https seemed to help.

Instructions from start to finish (mostly)…

Create virtual server

• Start with ubuntu minimal server install 19.10
  • Because 18.04 LTS doesn’t have PDFtk, without using snap and other workarounds that caused me problems.
  • Choose at least 8GB disk
  • If choosing the LVM option, https://askubuntu.com/questions/1106795/ubuntu-server-18-04-lvm-out-of-space-with-improper-default

# We need to resize the logical volume
to use all the existing and free space of the volume group

$ lvm

lvm> lvextend -l +100%FREE
/dev/ubuntu-vg/ubuntu-lv

lvm> exit

# And then, we need to resize the file
system to use the new available space in the logical volume

$ resize2fs /dev/ubuntu-vg/ubuntu-lv

resize2fs 1.44.1 (24-Mar-2018)

Filesystem at /dev/ubuntu-vg/ubuntu-lv is
mounted on /; on-line resizing required

old_desc_blocks = 1, new_desc_blocks = 58

The filesystem on
/dev/ubuntu-vg/ubuntu-lv is now 120784896 (4k) blocks long.

# Finally, you can check that you now
have available space:

$ df -h

Filesystem                         Size  Used Avail Use% Mounted
on

udev                               3.9G     0  3.9G   0% /dev

tmpfs                              786M  1.2M  785M   1% /run

/dev/mapper/ubuntu--vg-ubuntu--lv  454G  3.8G  432G   1% /

Install CUPS

1. Openssh-server was installed by default, Login and get IP address
   >ip addr show
2. Install cups
   #sudo apt install cups
3. Add my local user to cups lpadmin group
   usermod -aG lpadmin <myusername>
4. Configure cups
   1. I had problems with cups rewriting the config files I’d changed by hand when the server rebooted. The solution is NEVER EDIT THE CUPS CONFIG FILES WHEN THE SERVER IS RUNNING!
      systemctl stop cups.service
   2. Configure following in /etc/cups/cupsd.conf
      Listen *:631 
   3. Comment out the other listen directives. *:631 listens on all connections but you can also restrict to a specific network with 192.168.1.230:631
5. Need allow access to the web GUI and web admin GUI by adding an ‘Allow all’ line to cupsd.conf. Note: This may not be a good idea if you can’t trust every device on your network. In that case I think you can restrict access by IP address or other auth methods.

<Location />
Order allow,deny
  Allow all
</Location>

<Location /admin>
  Order allow,deny
  Allow all
</Location>

systemctl start cups.service

1. Turn off discovery of remote printers
   • There seems to be an issue with remote discovery of printers. They disappear through reboot and maybe other triggers.  So for now I’m manually adding the network printers in the hope they are retained (this has worked so far…)

systemctl stop cups-browsed.service
 

/etc/cups/cups-browsed.conf

BrowseRemoteProtocols none
# was BrowseRemoteProtocols dnssd cups

systemctl start cups-browsed.service

Add printers via the CUPS web interface

1. Go to web interface in browser, http://<ip>:631

Check box “share printers connected to this system”

  + check allow printing from the internet

Nb: it will redirect you to https pages then ask for your username/password as per the account you added to the lpadmin group.
I decided to call my print server “Mars” and setup up print queues using the format ‘server’+’printer model name’+’optional descriptive label’

1. Add network printers manually to print server.
   1. Administration > Add Printer
   2. Other network printers > Internet Printing Protocol (ipp)
   3. Connection address: “ipp://<ip>:631”  where IP is the printer IP. EG: ipp://192.168.1.220:631
   4. Name “mars”+model+(dash)+description”, eg “marsP6035” for the default printer “marsP6035-letterhead” for magic letterhead, or maybe “marsP6035-duplex” for a forced duplex mode
   5. Leave the description blank (it appears in the  windows print dialog boxes, better for us to have useful description detail as part of the name).
   6. Check the box ‘share this printer’
   7. Use the manufacturer provided PPD file (mine all came from the manufacturers install files, in a sub directory called ../linux/eu/)
   8. Test print to make sure it works

Footnote: Adding printers for the magic letterhead has been problematic. The last printer I set up needed to be set up as described here https://www.steveroot.co.uk/2022/11/03/automatic-letterheads-from-a-printer/ using generic CUPS driverless drivers rather than the manufacturer provided PPD.

Install PDFtk

1. Apt install pdftk
2. disable aparmour, it seems to block the scripts we’re going to create. I guess there’s an easy way to allow them but I don’t know what it is.

AppArmor can be disabled, and the kernel module unloaded by entering the following:
sudo systemctl stop apparmor.service
sudo update-rc.d -f apparmor remove

To re-enable AppArmor in the future enter:
sudo systemctl start apparmor.service
sudo update-rc.d apparmor

Add the magic letterhead code

1. The knowledge of this came from from http://technik.blogs.nde.ag/2012/08/28/watermarking-printouts-in-the-linux-world/ but I have slightly modified parts to suit my needs
2. Copy your Letterhead.pdf artwork into /etc/cups
3. Setup watermark scripts in /usr/lib/cups/filters named: letterheadwatermark

Chmod 755

#!/bin/bash

logfile=/tmp/watermarkpdf.log
watermark=/etc/cups/Letterhead.pdf

tempdir=$(mktemp -d)

echo $(date) “$0 $* (tempdir: $tempdir)” >> $logfile

# Command line arguments
job=”$1″
user=”$2″
title=”$3″
numcopies=”$4″
options=”$5″
filename=”$6″

if [ -z “$filename” ] ; then
        filename=”-”
fi

if [ $# -ge 7 ]; then
        cat $6 > $tempdir/ps.in
else
        cat > $tempdir/ps.in
fi

# convert Postscript to PDF
/usr/bin/ps2pdf $tempdir/ps.in $tempdir/pdf.in 2>>$tempdir/err

# watermarking.  ‘stamp’ puts letterhead over document, ‘background’ puts it under. Some documents send all white background so letterhead will not show through white areas.
/usr/bin/pdftk $tempdir/pdf.in stamp “$watermark” output $tempdir/pdf.out 2>>$tempdir/err

# convert PDF to Postscript
/usr/bin/pdftops $tempdir/pdf.out – 2>>$tempdir/err

# clean-up. I don’t remove the tmp files as they are very useful to find out what stage of this script is failing
# rm -rf $tempdir

From <http://technik.blogs.nde.ag/files/2012/10/watermark.sh>

1. In /etc/cups create a link to the cups filter folder, eases finding things later
   Ln -s /usr/lib/cups/filter/ cups_filter_directory
2. Copy script into filter folder, chmod 755 & chown to root
3. Restart again: systemctl restart cups.service
4. I’m using the kyocera PPD from <myserver>/software/printer then inserting cupsfilter line to make it print a letterhead. I wanted to use the IPP everywhere PPD (default in cups) but that didn’t work. I suspect the IPP everywhere PPD gets the first input as PDF whereas the kyocera PPD gets the first input as postscript. I tried skipping the PStoPDF but that didn’t work either and I stopped searching once I got it working with the kyocera PPD
5. Modify the printer PPD (/etc/cups/ppd/<your-print-queue.ppd> to call the script.
   systemctl stop cups.service
   then add this as second line:
   *cupsFilter: "application/vnd.cups-postscript 100 letterheadwatermarkpdf"
   then
   systemctl start cups.service

Add the printer to the client

1. Add printers to clients
   1. Printer and scanners > add printer or scanner
   2. From the printers discovered, select printer, eg: “marsP6035 @ marsprint”. Selecting the @server i’m guessing is selecting the IPP service.
   3. Send a test print, hope it works 🙂
2. Alternative method that had issues of print being scaled down, perhaps near a5 printing instead of a4 before the stamp/watermark applied. Ps2pdf command seems to be the issue here.
   1. Add printer, The printer that I want wasn’t listed, select a shared printer by name
   2. Paste the url from the printers page on the server, it will be like:
      http://192.168.1.230:631/printers/marsP6035
   3. Note: not https (sometimes that seems to fail, not sure why)
   4. Driver: Microsoft > Microsoft PS Class Driver
3. Add printer directly to computer with manufacturer driver file
   1. This is useful because the Kyocera drivers allow more print options and control, eg paper type, make poster from multiple pages, etc.
   2. Test print… Hopefully this works too !