Pages - PDF - PNG
Here is a short script for those who dabble in graphic design in Pages, and print-on-demand (POD).
1 Make your design in Pages.
2 Under File menu go to Export to (Exporter vers... in French) and chose PDF.
3 Open the PDF file in Preview, the Mac does it by default.
4 Again, under the File menu slide down to Export (Exporter...) and in the opening window click on the Format menu and chose PNG. Here, set Resolution to 301 pixels per inch, which is an industry standard for professional/commercial printing.
5 Save, open the PNG file and under the View menu open Tool Bar (or Markup Toolbar), in the tool bar click on Alpha, second from left at the top.
6 Drag the cursor over the background, and when the blinking cursive line appears, click delete. You will get a checkered grey background. This is a transparency. Now, check for the white spots inside some letters of your 'slogan' design, like A, D, P, O, B. These have to be 'whiped' out with Alpha too. Click and drag, then click Delete. Once you're done with these, save your file and it's ready for uploading to whatever POD site you use.
Once you get to grips with this, it takes less than five minutes from doing a text slogan in Pages to uploading a ready design for a mug or a tee-shirt.
And here you can see one of my recent designs on CafePress, one of the top POD sites. I have used the Pages to PNG method described above.
Good luck with this!