What are Postcript Points and how do they relate to pixels, please?

[ernestbywater]

G'day All,

Can anyone tell me what the heck Lulu means by Postcript Points - I can't find anything about them in the bleeding Help or FAQ area. I'm revising a project that has both a printed book and a PDF ebook version. The last time I uploaded to Lulu I loaded the one Print Ready PDF file and the one Cover ART image set to the requirements for the Printer; and they did both types of books. Now they have them as two projects and I have to load them TWO Cover Art images as the PDF ebok thing goes on about 648 Postcrip Points being the maximum size ( no height or width dimensions or DPI), and it rejects the Cover Art that is perfect for the printed book, and is the same size and DPI as the old cover art.

I can't amend the Cover Art for the old projects or a new project until I have some sensible information on the image DPI, pixels, width and height. So, Please, can someone tell me what Postscript Point is and how it realtes to an intelligent description of an image?

Regards

Ernest.

[Ken Anderson]

They are just another unit of measurement. 72 points equal 1 inch. Lulu wll normally state a required image size in points, inches and cm. just read what's on the screen. Images for eBook covers (marketing images) should be 72dpi, 96dpi or 150dpi.

[ernestbywater]

G'day Ken,

Thanks for that info, I'm used to points as in points per square inch and point size for fonts, also used to dealing with pixel sizes and dpi - but never heard of a Postcript Point before. The first place I came across it was the cover section of the e-book wizard, and it says, simple:

quote

One-piece cover requirements:

Your file must be a PDF, JPG, GIF, or PNG
Total cover size: 432 X 648 Postscript points (6.00 " X 9.00 ")

end quote

I checked the help files and the FAQs, and got no help or better descriptions. The previous cover art files for the printed versions were used for the original submissions and they give dpi and pixel sizes for each dimension - using a 300 dpi.

Now, when I adjust the image to be 150 pixels per inch and the right number of pixels for the page size, I get told the number of Postcript Points is too low for the image, as it wants 432 x 648 Postcript Points - it's driving me crazy trying to work out how this relates to the image in pixel dimensions and ppi, or dpi, the image manipulation program can handle both of those, but not these Postcript Points - it's not heard of them either. And the wizard is driving me crazy.

Oh, well, I'll just have to spend time with the wizard open while I mess about amending the image to try various sizes of image and dpi combinations until I find one that works.

regards,

Ernest