Preparing a POD cover file
Print on Demand (POD) services require your book cover files to be in the correct format. You will need to consider a number of things before you upload your file.
POD Service Requirements
Make sure that your book's text and cover are saved as separate files. Your cover file should include the front cover panel, as well as the side and back panels (so that it is one page showing the back of the book, the spine and the front).
The spine size is dependent on the number of pages, the thickness of the paper stock used for the pages, and your chosen binding style. If you change any of these three, you will need to make the relevant change on your cover file to amend the spine size.
The majority of POD services accept PDF files. It is important to note that your files must have fonts embedded otherwise they could be rejected. You can check for this by opening your PDF file in Adobe Acrobat , selecting the File dropdown and then Properties. All fonts will be listed in the Fonts tab. Any font without "Embedded" or "Embedded Subset" next to it is an unembedded font and needs to be changed before submitting the file.
When saving your PDF file, make sure that it does not contain any bookmarks, comments, invisible objects or metadata which can interfere with printing.
You will need to include a bleed on your cover file, which means the images being slightly larger than the boundary lines on all sides (see below). A bleed is typically 3mm, but this varies from service to service.
The cover file should be saved to a resolution of at least 300dpi (dots per inch).
PDF files need to be saved as flattened PDFs with no transparency.
If you don’t want to create a cover file from scratch using graphic design software such as Adobe Photoshop, there is other software available that provides standard templates. These include:
- IngramSpark Cover Template Generator . It is worth noting that IngramSpark requires you to have a unique ISBN code for your book as well as a barcode on the cover file.
- Adobe InDesign.
- Amazon's CreateSpace Cover Designer. This provides a number of book templates that include trim and bleed margins, which saves you time and effort when creating your cover.
As mentioned above, your cover image needs to include back, spine and front covers in the one image. You will need to measure the exact trim size, spine width and include a bleed. You will also need to centre it horizontally and vertically.
To calculate the minimum cover width (for the overall image), you should use the following: Bleed + Back Cover Trim Size + Spine Width + Front Cover Trim Size + Bleed.
To calculate the minimum cover height required: Bleed + Book Height Trim Size + Bleed
The sizes vary depending on the number of pages in your book, the size of the print that you choose and the paper stock that you opt for. POD services will help you establish these sizes for your calculations.
During the printing process, there can be a degree of document movement that may lead to variations in how your book cover is printed on the page. In fact some companies, such as IngramSpark, allow for a 2mm difference in movement per book. To counterbalance these changes, a “bleed” must be set up on your cover file.
A bleed is where the cover image extends beyond the printable area. For most POD services, a bleed of 3mm is standard. Without the bleed, a movement during printing could cause white margins to show on your book cover or your title to be partially cut off.
To make sure your book cover is printed to the quality that you need, save your images to the best resolution possible (at least 300dpi). Colour images should be converted and saved in the CMYK (Cyan, Magenta, Yellow and Black) colour space. This will ensure the most accurate reproduction of colours.
Monochrome images must be saved to greyscale.
If colour accuracy is essential to you, it is a good idea to request a full production proof prior to ordering your final books. Most POD services advise this, and charge the cost of printing plus postage.
The standard colour scheme for pictures is RGB (red, green and blue), and it is how we usually view images on a screen. The CMYK colour scheme (cyan, magenta, yellow and black) is used for print.
There are some colours that can be viewed in RGB mode that are impossible to achieve in CMYK mode. When you are preparing files for print, make sure that you are working in CMYK mode and make any colour corrections in that mode.
Always ask for a high-resolution proof copy before finalising your book for publication to ensure that your images are printed correctly.
There are some common issues when printing in CMYK, including:
- Blues being printed as purple. You should ensure that your cyan and magenta values are at least 30 points apart (for example, C100%, M70%, Y10% and K10%). When the values for cyan and magenta are closer than 30 points apart, the blues can turn to purple during printing even when they look right on your screen.
- Greys may not print as a neutral colour. This is because creating grey using all four of the CMYK colours can add variations to the grey. More magenta can cause a warmer pinkish grey, more cyan can create a blueish grey and too much yellow will produce a brownish grey. To overcome this, you need to make your greys using the black element of CMYK, which is K (key). Light grey can be achieved between 10-30%, medium grey between 40-60% and dark grey between 70-85%.
- Blacks may have a colour hue. This is similar to the grey problem. A standard, neutral black has the CMYK values of 60% cyan, 40% magenta, 40% yellow and 100% black.