With the Print-on-Demand process used by Lightning Source/IngramSpark, books are printed and manufactured in a one-off model using both automated and manual processes. Each book is manufactured in its entirety, every time an order is placed. Due to slight changes in production from day to day, variations in printing and manufacturing are a common occurrence.
We make provisions for and indicate in our company documentation, that there may be up to a 1/16” shift or +/-0.1 color density variation on any book manufactured by Lightning Source/IngramSpark. Orders outsourced to other printers we have partnered with will also meet Lightning Source/IngramSpark print requirements and acceptable variations as described below.
Below is a list of the most common manufacturing variances.
Due to the nature of inkjet printers, interior files may print with thin white lines/voids (1/600 of an inch in width) through images and/or graphics.
These voids should not exceed one or more of the following criteria: voids consisting of two adjacent lines that result in a void of 1/300 of an inch or greater or more than three white lines/voids per page.
A barcode, inserted on the last page of the book facing the inside back cover, is used as part of our manufacturing process to match up the interior book block with the cover on the print floor. Also, we are required as a manufacturer to show where the book was produced. The bar code provides information for that book throughout the manufacturing process. This barcode also assists us during an investigation if there are any manufacturing issues with the finished product.
Books manufactured by Lightning Source/IngramSpark are printed in a climate-controlled environment to minimize any type of moisture-based damage. However, when the units leave the print facility they are exposed to different climate conditions, as well as different levels of pressure. Mild waves of the pages may occur under these circumstances and are an unavoidable issue.
Fold creases along the spine edge of the front and back cover of a book are a common occurrence due to our binding processes. Fold creases can be more noticeable with matte laminated covers. Cover designs with heavy ink coverage are more prone to lamination adhesion problems in the crease area of the binding.
Laminate popping, where the matte lamination does not adhere to the cover in some places, usually happens on dark covers (dark blues, dark reds, black) and is sometimes caused by the cover file being set above 240 TAC (Total Area Coverage = density). To avoid this problem, the CMYK's total value should not exceed 240%.
Printer marks along the gutter side of the interior pages are used for calibration and help to keep ink levels consistent. These marks must be positioned just outside of the gutter edge and cannot be moved to an area that is trimmed off. The spines are milled prior to binding to minimize the visibility of the marks. They aren’t very visible, but printed books with slightly visible printer marks, within the gutter, may be considered within our production variance.
Minor manufacturing defects can occur from time to time. Below is a list including, but not limited to, defects that when minor, are not considered to make a product unsellable:
- Cover scratches
- Smudges in the lamination (Usually this is the glue that can be wiped off with a damp cloth)
- Dents in the cover
- Folded pages
- Lamination creases or scored hinges
- Gutter read marks
We recommend that you spot-check more than one carton of books if a manufacturing error or defect is suspected. If you feel the books received are not in good condition, instructions and additional information are available in our Order Claims article.
Books manufactured using print-on-demand digital printers may differ slightly from books manufactured by an offset printer.
Larger orders of 750+ units placed with the Extended Print service level may be sent to an offset vendor and may not be manufactured by Lightning Source/IngramSpark. Print On Demand digital printing and offset printing processes are not identical so the final products may not be exactly alike. You may see slight variations in areas like color or binding of the printed product due to the different printing methods used.
Due to the nature of Print on Demand production, there can be a certain amount of variance in the "look" of a book from order to order. Unlike offset printing where the offset printer sets up its print lines to produce one particular type of book over and over again, our print lines are set up to cater to a number of different book types, trim sizes, interior color settings, etc. As such, there can be some visible differences in a book from order to order. These variations occur due to differences in printing location and equipment used to produce separate orders.
Additionally, we utilize multiple printers at each of our facilities and printing can vary from printer to printer. Although we make every effort to calibrate our machines to match one another, each machine will print slightly differently from one another as no two printers are identical. We also indicate in our company documentation that there will likely be color variations across cover types (Perfectbound, Case Laminate, and Jacketed Hardcovers) between orders.
Color variations are subjective, as everyone sees color differently. Rather than focus on color variation subjectively, Lightning Source assesses color variation objectively. We measure Delta E readings, which is simply the difference between two numbers. The print industry standard for Delta E is 5.0 or less. However, Lightning Source actually exceeds print industry standards by setting our pass/fail Delta E at less than 3.0.
On both our inkjet book block presses and our toner-based cover presses, we use a system that compares current Delta E readings to the original ones recorded when the equipment was brand new and in a pristine state. The maximum difference between these two numbers must be less than 3.0 for the press to be in spec.
It is important to keep in mind that light shades and backgrounds are more likely to show visual variation than darker colors because it only takes a slight change in density or dot size for a light shade to show color variation. When a book is printed, the ink absorbs slightly into the paper, resulting in a minor loss of detail due to dot gain (ink spreads when it hits the sheet). Even if our Delta E readings are well below 3.0 (meaning the equipment is in spec), light colors can still show a subjective visual variation despite the equipment being in spec.
The page count of the printed book may increase, depending on the printed signature.
There are times during the manufacturing processes of printing and binding when a book may need to have additional pages added, which you are not charged for. (Example: the stored file is 26 pages (not divisible by 4 or 6) and 2 pages are added when printing as four-page or 4 pages are added when printing as six-page).
**A signature is a group of pages that are printed on both sides of a single sheet of paper that once folded, trimmed, bound, and cut, become a specific number of pages depending on the page size and the size of the press sheet.
Premium Color book interior files are processed with page counts divisible by 2 and printed with page counts divisible by 4.
Lightning Source will automatically add blank pages when printing and binding a book, if necessary. If you want to ensure no blank pages are added during the manufacturing process, the book’s page count should be divisible by 12.
What is an acceptable variance in the trim size of a book? With our print-on-demand technology, each book is made in its entirety each time an order for the book is received. Because of this, each book may or may not be an exact copy of the previously manufactured book. There may be a minimal amount of variance in the “look” of a book from order to order because the book is being re-manufactured each time. There may be up to a 1/16” variation in the trim size of any book manufactured by Lightning Source.
RGB blue is a vibrant and beautiful blue--however--because we cannot print in RGB, the color must be converted to CMYK. When RGB blue is converted to CMYK, it becomes a combination of 99.6% Cyan and 95.7% Magenta. This conversion results in a ratio of Cyan to Magenta that produces a purple hue, and this is how it will print. CMYK cannot reproduce that shade of blue. The computer and software will substitute the closest color to it.
It's best to choose your blue in CMYK, and to be careful how much Magenta is in the values range––especially if the Magenta is as high as, or close to the same value of Cyan.
High ink density titles are those titles where a single or double-sided page(s) within the interior of a book contains a high level and/or area of Black or CMYK ink saturation, which, when printed on Lightning Source printing equipment, ultimately causes curling of pages, wrinkled pages, or may cause streaks. IngramSpark may be unable to fulfill a B&W or Color print order due to areas of high ink density/heavy ink coverage within these titles. When we identify a title with high-density ink coverage, we will move the title to Premium Color at no additional charge to the publisher for a period of 30-days. After 30 days, the publisher can elect to either; (i) cancel the title or (ii) agree to a new print cost per unit and continue to print orders as Premium Color. Print cost per unit to be agreed on a title-by-title basis, as titles are identified, due to the increased manufacturing costs associated with these titles.
Files should not have TAC (Total Area Coverage) that exceeds 240%. Total area coverage (TAC) is the combined value of all CMYK. For example, recommended rich black is:
- C (cyan) 60%
- M (magenta) 40%
- Y (yellow) 40%
- K (black) 100%
When totaled, it equals 240%.
This can be viewed in Acrobat Pro by opening the file and going to:
- View/Tools/Print Production/Open
- Select Output Preview
- Check the box for Total Area Coverage
- Change the number to 240. This will highlight anything in the file that has a TAC higher than 240. It defaults to lime green, but you can change the color.
Alternatively, you can run a preflight check for the file in Acrobat Pro. We recommend making any adjustments to the original art files and updating those files in InDesign.
To prevent oversaturation of paper within your book, Lightning Source recommends no more than a 40% difference in front-to-back coverage.* In the event that we cannot print your black and white, or color book, due to saturation issues, we do offer Premium printing. For specifications and pricing, please review your print and ship calculator under the title in your account.
We use high-quality inkjet and laser printers at our print facilities; however, due to the nature of these printers, there may be some variation in the look of the covers we print.
If you have concerns or questions about the look of your book, please email a photo of the book to the support team for review.
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