With these 2 scripts in Caja context menu, you can print files directly, there's no need to open them :
Check that Cups is installed.
1) Print ALL the PDF files contained in a folder.
With this script, all pdf files are printed, even if only one is selected. It works with the default printer.
for FILE in *.pdf *.PDF ; do lpr "$FILE" ; done
Copy to a text editor, save as "Print ALL PDFs in the folder" and give permission to allow executing file as program.
Put it in the script folder of Mate (CTRL H to show hidden files):
so you can have it in the context menu - Script.
2) Print selected PDF files (it works for me with PDF, JPEG and PNG, TXT but not with the libreoffice formats):
echo "$CAJA_SCRIPT_SELECTED_FILE_PATHS" | while read file
lpr -P "$printer" "$file"
Do the same procedure to allow execution and put it in the script folder.
Replace the printer name, which can be obtained by the command on terminal
lpstat -p -d
or see the /etc/cups/printers.conf file