Print options cannot be changed after publication.

Paper choice
You can choose from:
– Black ink on white paper
– Black ink on cream paper
– Standard coloured ink on white paper (not available for hardback editions)
– Premium coloured ink on white paper 

Standard colour printing costs more than black and white options, while premium colour printing is the most expensive. Standard colour is not recommended for image-heavy books or those with dense illustrations. 

A screenshot from the KDP publishing process for paperback books. The heading is 'Print Options' and there are multiple sections. 

Section 1 - Ink and Paper Type. There are four options.
Option 1: black and white interior on cream paper. 
Option 2: black and white interior on white paper.
Option 3: standard colour interior on white paper.
Option 4: premium colour interior on white paper.

Section 2 - Trim Size. 
6 x 9 in (15.24 x 22.86 cm) is automatically selected or there is a button to 'Select a different size'. 

Section 3 - Bleed Settings. 'No Bleed' is automatically selected and there is a button for 'Bleed'. 

Section 4 - Paperback cover finish. 'Matte' is automatically selected and there is a button for 'Glossy'.
Print options for paperback books
A screenshot from the KDP publishing process for hardback books. The heading is 'Print Options' and there are multiple sections. 

Section 1 - Interior and paper type. There are three options.
Option 1: black and white interior on cream paper. 
Option 2: black and white interior on white paper.
Option 3: premium colour interior on white paper.

Section 2 - Interior Trim Size. 
6 x 9 in (15.24 x 22.86 cm) is automatically selected or there is a button to 'Select a different size'. 

Section 3 - Bleed Settings. 'No Bleed' is automatically selected and there is a button for 'Bleed'. 

Section 4 - Paperback cover finish. 'Matte' is automatically selected and there is a button for 'Glossy'.
Print options for hardback books

Find out  more about paper and ink choice here: https://kdp.amazon.com/en_US/help/topic/G201834180

Trim
Trim size refers to the physical dimensions of your printed book.
Make sure to select the trim size that matches the dimensions of your manuscript file.
Note that hardback editions have fewer trim size options than paperback. 

Screenshot of KDP paperback trim sizes. 

Most Popular Standard Trim Sizes. Option 1: 5 x 8 in (12.7 x 20.32 cm). Option 2: 5.25 x 8 in (13.34 x 20.32 cm). Option 3: 5.5 x 8.5 in (13.97 x 21.59 cm). Option 4: 6 x 9 in (12.24 x 22.86 cm).

More Standard Trim Sizes
Option 5: 5.06 x 7.81 in (12.85 x 19.84 cm). Option 6: 6.14 x 9.21 in (15.6 x 23.39 cm). Option 7: 6.69 x 9.61 in (16.99 x 24.4 cm). Option 8: 7 x 10 in (17.78 x 25.4 cm). Option 9: 7.44 x 9.69 in (18.9 x 24.61 cm). Option 10: 7.5 x 9.25 in (19.05 x 23.5 cm). Option 11: 8 x 10 in (20.32 x 25.4 cm). Option 12: 8.5 x 11 in (21.59 x 27.94 cm).

Non-Standard Trim Sizes
Option 13: 8.27 x 11.69 in (21 x 29.7 cm). Option 14: 8.25 x 6 in (20.96 x 15.24 cm). Option 15: 8.25 x 8.25 in (20.96 x 20.96 cm). Option 16: 8.5 x 8.5 in (21.59 x 21.59 cm). 

Self-Define Trim Size
Options to create a custom trim size.
Trim size options for paperback
Screenshot of KDP hardback trim sizes. 

Option 1: 5.5 x 8.5 in (13.97 x 21.59 cm). Option 2: 6 x 9 in (15.24 x 22.86 cm). Option 3: 6.14 x 9.21 in (15.6 x 23.39 cm). Option 4: 7 x 10 in (17.78 x 25.4 cm). Option 5: 8.25 x 11 in (20.95 x 27.94 cm).
Trim size options for hardback

Bleed
Bleed refers to printed elements, such as images, that extend all the way to the edges of the page. If you want the images in your book to reach the edges of the page, you must extend them past the trim line.
Note – If your manuscript includes a bleed, you must save it in PDF format.

Amazon recommends using the following formula to calculate your page width and height with bleed:

InchesCentimeters
(Trim height) + (0.125″ x 2 (bleed)) = Page height with bleed
(Trim width) +(0.125″ (bleed)) = Page width with bleed
(Trim Height) + (3.2 mm x 2 (bleed)) = Page height with bleed
(Trim Width) + (3.2 mm (bleed)) = Page width with bleed

Cover Finish
Covers can have a glossy or matte finish. 

A glossy finish is shiny and commonly used for textbooks, children’s books and non-fiction. 
A matte finish has minimal sheen and is often used for fiction. 

Here is a useful video showing the difference between the two on a KDP-printed hardcover: https://youtu.be/yYNXQpeCWLA

Find out more about trim size, bleed and margins here: https://kdp.amazon.com/en_US/help/topic/GVBQ3CMEQW3W2VL6