# Create blank page using Ghostscript
# '/etc/ImageMagick-6/policy.xml' contains a policy setting rights
# to "none" for pattern "PDF" under the coder domain. This should be disabled
# (by commenting out) in order to use ghostscript for pdf. Note security concerns.
user:~$ convert xc:none -page A4 blank.pdf
user:~$ convert xc:none -page 842x595 blank.pdf  # horizontal

# Create blank page using 'ps2pdf'
user:~$ echo "" | ps2pdf -sPAPERSIZE=a4 - blank.pdf

# Append blank page, uses 'pdftk'
# Converts 'file.pdf' -> 'notes_file.pdf'
user:~$ export FILE=file.pdf
user:~$ pdftk A=$FILE B=blank.pdf cat A1-end B output notes_$FILE.pdf

# Interleave blank pages, uses 'pdftk'
user:~$ export FILE=file.pdf
user:~$ export NUM=`pdftk $FILE dump_data | grep NumberOfPages | awk '{print $2}'`
user:~$ pdftk blank.pdf cat $(printf '1 %.0s' $(seq $NUM)) output multiblank.pdf
user:~$ pdftk A=$FILE B=multiblank.pdf shuffle A B output notes_$FILE