Duplex Printing - Officejet 7610

[baronmax]

This is what finally worked for me on Mac Air El Capitan with wireless HP7212...

1. Select system preferences > printers & scanners

2. Right click in the printers window and click on reset printer system (this will delete all your printers)

3. Click +

4. Hopefully it will show the Officejet 7610 already on your network

5. Select it

6. Select 'use'.  

- At this point I first selected Airprint.  In this duplexing results in second page being upside down (so you might not want to bother doing this)

Then I added a second printer (same steps as above)

- At point 6 I selected HP Officejet 7610 series

- Duplexing now works! (ie the second page is printed the same way up as the first front page)

On scaling: In preview if you make sure it prints at 100% size (in the dialogue boxes) then I think the scale will be ok for a single sheet or duplexing.  It defaulted to 89% when I tried it first so you have to change this.  (This maybe because I was printing to the margins).  If you want to print to the margins of the page (like for example the 12" ruler at http://printable-ruler.net/wp-content/uploads/2015/08/ruler-12in-30cm-A4-metallic.pdf) the top and bottom will be cut off (if still printing at correct size using standard A4 as paper type).  You can still print to the margins using 'A4 borderless' but only in single sided.  If you try to print this double sided the driver makes you scale it to US legal (wrong) although it does tell you its doing this.

EDIT: If you select 'edge to edge' A4 or A3 it seems to scale correctly, single or double sided!  And actually the scale was fractionally out above using borderless A4 when I checked with a real ruler but seems ok with this.

Jeezz HP sure don't make it easy....