What language version of Thunderbird are you using? en-US or en-GB ?

When you go to File > Page Setup > Margins & Header/Footer tab At the top does it say 'Margins (millimeters)' or 'Margins (inches)' ?

Thanks for quick reply!

I'm not sure where to find TB locale, but in Tools / Options / Start page the Location URL string contains "?locale=en-GB". In prefs.js there are 6 instances of "en-AU", all relating to dictionaries, but no instances of "en-GB" or "en-US".

Page setup margins are specified in inches.

I'm using English (British) downloaded from here:

• https://www.mozilla.org/en-US/thunderbird/all.html

English (British) is auto setup to use millimeters in File > Page Setup. it is also auto using A4 instead of Letter when printing.

The English (US) version is auto setup to use inches and Letter.

Options: Suggest you first try to change the size type then inches to millimeters if desired

Tools > Options > Advanced > General tab click on 'Config Editor' button

In top search type: size look for this line: print.printer_namexx.print_paper_size_type; Value = 0 Value 0 = A4 Value 1 = Letter

print.printer_namexx.print_paper_size_unit; Value = 1 Value 0 = inches Value 1 = millimeters

Note that although I'm using A4 and millimeters with these margin settings in Page Setup: Top, Left, right on 12.7 Bottom on 20.0

In the Config Editor this is the settings shown: print.printer_EPSON_SX510W_Series.print_margin_left; Value = 0.5 print.printer_EPSON_SX510W_Series.print_margin_bottom; Value = 0.787500023841858 print.printer_EPSON_SX510W_Series.print_paper_height; Value = 11.00 print.printer_EPSON_SX510W_Series.print_paper_width; Value = 8.50

I expected the height and width to change when the chnage of 'size_type', but it didn't and does not seem to effect the outcome as the printer uses A4. I have tried leaving the default as above and also changing the Values to what you would expect to be correct for A4: eg: print.printer_EPSON_SX510W_Series.print_paper_height; Value = 11.69 print.printer_EPSON_SX510W_Series.print_paper_width; Value = 8.27

however, this does not seem to produce anything any different.

The real difference is in choosing the size_type

re: I have added "print.postscript.paper_size A4" to prefs.js - no improvement. I believe linux systems use the postscript options.

Thanks again for your reply.

At first I did not realize 'namexx' was a placeholder. I could not add new statements in about:config, so I edited prefs.js, placing the two new 'namexx' lines in correct alpha position. The lines did not even appear in about:config, so TB obviously knows an unofficial statement when it sees one.

The statements for my printer already had the correct values, eg print.printer_DocuPrint_CM205_fw.print_paper_size_type;0 print.printer_DocuPrint_CM205_fw.print_paper_size_unit;1 Still prints to Letter, although I recently found the Margins dialog for the printer, which is in mm.

Interestingly the statements for my other 'printer', PDF999, are of shorter format, despite having been system-generated presumably when it was installed years ago:eg printer_PDF995.print_paper_size_type;0

My next step was to download and install the UK version of TB 31. Problem remains the same. The new installation obviously inherited a lot of config, but it did remove my 'namexx' lines from prefs.js.

Maybe I have to uninstall TB (and backup prefs.js somewhere else), then do a clean install of the UK version. A pain as I have a number of identities, although I see they are in prefs.js (searching on identity), so maybe I can paste them in after.

re: namexx' where this was written, this refers to the name of your printer. For example in my case 'namexx' = EPSON_SX510W_Series: eg: print.printer_EPSON_SX510W_Series.print_paper_size_type;0 and printer_EPSON_SX510W_Series.print_paper_size_type;0

which means both the command from Thunderbird and the printer itself are set to use A4.

I also have an older printer which i used to use, but do not use now and there is an entry: printer_EPSON_Stylus_CX6400.print_paper_size_type;0 but this printer does NOT have this next line - because it is not set up as default printer; so not used: print.printer_EPSON_Stylus_CX6400.print_paper_size_type;0 So only the default used printer will have a line like the above.

The following lines are all the entries for my current default printer. You should have probably the same except that the printer name will be: DocuPrint_CM205_fw and not what I have: EPSON_SX510W_Series

So you could work through each of your entries and make sure you have the same as me.

     print.printer_EPSON_SX510W_Series.print_bgcolor: false
     print.printer_EPSON_SX510W_Series.print_bgimages: false
     print.printer_EPSON_SX510W_Series.print_colorspace:
     print.printer_EPSON_SX510W_Series.print_command:
     print.printer_EPSON_SX510W_Series.print_downloadfonts: false
     print.printer_EPSON_SX510W_Series.print_duplex: 0
     print.printer_EPSON_SX510W_Series.print_edge_bottom: 0
     print.printer_EPSON_SX510W_Series.print_edge_left: 0
     print.printer_EPSON_SX510W_Series.print_edge_right: 0
     print.printer_EPSON_SX510W_Series.print_edge_top: 0
     print.printer_EPSON_SX510W_Series.print_evenpages: true
     print.printer_EPSON_SX510W_Series.print_footercenter:
     print.printer_EPSON_SX510W_Series.print_footerleft: &PT
     print.printer_EPSON_SX510W_Series.print_footerright: &D
     print.printer_EPSON_SX510W_Series.print_headercenter:
     print.printer_EPSON_SX510W_Series.print_headerleft: &T
     print.printer_EPSON_SX510W_Series.print_headerright: &U
     print.printer_EPSON_SX510W_Series.print_in_color: true
     print.printer_EPSON_SX510W_Series.print_margin_bottom: 0.787500023841858
     print.printer_EPSON_SX510W_Series.print_margin_left: 0.5
     print.printer_EPSON_SX510W_Series.print_margin_right: 0.5
     print.printer_EPSON_SX510W_Series.print_margin_top: 0.5
     print.printer_EPSON_SX510W_Series.print_oddpages: true
     print.printer_EPSON_SX510W_Series.print_orientation: 0
     print.printer_EPSON_SX510W_Series.print_page_delay: 50
     print.printer_EPSON_SX510W_Series.print_paper_data: 9
     print.printer_EPSON_SX510W_Series.print_paper_height: 11.00
     print.printer_EPSON_SX510W_Series.print_paper_name:
     print.printer_EPSON_SX510W_Series.print_paper_size_type: 0
     print.printer_EPSON_SX510W_Series.print_paper_size_unit: 1
     print.printer_EPSON_SX510W_Series.print_paper_width: 8.50
     print.printer_EPSON_SX510W_Series.print_plex_name:
     print.printer_EPSON_SX510W_Series.print_resolution: 0
     print.printer_EPSON_SX510W_Series.print_resolution_name:
     print.printer_EPSON_SX510W_Series.print_reversed: false
     print.printer_EPSON_SX510W_Series.print_scaling: 1.00
     print.printer_EPSON_SX510W_Series.print_shrink_to_fit: false
     print.printer_EPSON_SX510W_Series.print_to_file: false
     print.printer_EPSON_SX510W_Series.print_unwriteable_margin_bottom: 0
     print.printer_EPSON_SX510W_Series.print_unwriteable_margin_left: 0
     print.printer_EPSON_SX510W_Series.print_unwriteable_margin_right: 0
     print.printer_EPSON_SX510W_Series.print_unwriteable_margin_top: 0

Hi Toad-Hall,

A few differences, most of them trivial, I think:

print.printer_EPSON_SX510W_Series.print_margin_bottom: 0.5, not 0.787...

print.printer_EPSON_SX510W_Series.print_paper_data: 1, not 9. (In my config, my two current printers are set to 1, and all my old disused printers were set to 9. I;m surprised to see your setting of 9 for this item.)

print.printer_EPSON_SX510W_Series.print_paper_height: 11.69, not 11.00

print.printer_EPSON_SX510W_Series.print_shrink_to_fit: true, not false (I think mine may be wrong, since scaling is set to 1.00, and shrinking doesn't make sense).

And finally I have an extra line not in your config: print.printer_DocuPrint_CM205_fw.print_to_filename; This is redundant given print_to_file is false, but it appears for every printer, past and present.

But apart from print_paper_data, pehaps, I can't see anything which would cause my problem.