Problems setting up greeting card sizes on an Epson are common with OS X. The custom size needs to be set up carefully to avoid potential problems.

Do note that you may need to tweak the margins in the custom paper setup for your particular printer. To start, make the custom paper size with 0.25" margins on all four sides and make a test print. If the image is pushed in one direction, make a modification to your margins in the paper setup. Also make sure that your image is indeed centered on the canvas in Photoshop before making changes.

If the intial test is successful, you can try and set the margins to 0.15" on all sides to maximize your printing space.

An example of the Custom Page dialog box. Note the Printer Margins drop down menu. Some customers report that leaving it set to Printer Defined is OK. Others state the need to set custom margins like you see above. Start with this method and experiment as noted above.

§ GIMP DRIVERS CAN CAUSE TROUBLE!

Here's a link with some explanation and how to get rid of those pesky GIMPs