What's the Big Deal?
A few weeks ago we posted a crash course on Bible cover materials, and now we turn our attention to the interior of the Bible.
You may have seen buzzwords like opacity, PPI, ghosting, or readability flying around the internet, especially when it comes to “high-quality Bible paper.” So what’s the big deal? It’s just paper, right?
The production of Bible paper is so technical that only a handful of companies in the world make it. The average ESV Bible, without any extra study content, has more than 700,000 words, and the ESV Study Bible has over 2.2 million words! Arranging this much content in an organized, cohesive, and readable way is a remarkable feat in and of itself. Then there’s printing everything on paper—a challenge that can only be described as a lesson in paradoxes and chemistry. Once produced and run through massive printing presses, the pages are bound (sewn or glued), then finished off with a cover.
You could make the case that Bible printing is one of the most complicated printing projects in the world.
Here are some some key terms to know related to Bible paper:
Opacity: transparency of the page: measured by how much light shines through a sheet (measured by a numerical rating of 800–1,600)
Show-through: the degree to which print shows through on the opposite side of a page (often referred to as “ghosting”)
PPI (pages per inch): a measurement of the number of pages in an inch of paper (measured by a numerical rating of 70–90)
Formation: used in describing the degree to which the pulp and fibers of a sheet of paper are, or are not, evenly dispersed.
Lignin: an organic substance found in plant cell walls. Lignin is a fortifying substance, like a glue that binds fibers together and allows plants and trees to stand upright.
Titanium dioxide: the most widely used white pigment because of its brightness and very high refractive index; Titanium dioxide is employed as a pigment to provide whiteness and opacity to products such as paints, coatings, plastics, papers, inks, foods, medicines (e.g., pills and tablets) as well as most toothpastes.
Common Types of Bible Paper
There are three main categories of Bible paper:
- Brownish or oatmeal colored paper
- Most commonly used choice for books and newspapers because of its low production cost
- The lignin in groundwood paper begins to deteriorate when exposed to air and sunlight, causing the paper to yellow and become brittle
- Typically a thicker paper (low PPI) which means it has high opacity
- Commonly used in economy Bible editions
- Free sheet
- Most commonly used paper for Bible production
- A chemical process pulls out the lignin, which protects the paper from discoloration but decreases its opacity
- In order to improve the opacity, titanium dioxide (in powder form) is injected into the pulp
- Titanium dioxide increases opacity because of how it refracts/scatters light, thereby keeping light from shining through the page
- Increased titanium dioxide = increased opacity
- Increased titanium dioxide = increased cost
- Has high PPI compared to groundwood paper
- A middle ground: has gone through the free sheet process, but still has some groundwood pulp in it
- PPI is higher because of free sheet components
- Retains more opacity because of groundwood components
- Difficult to tell the difference between a blended and freesheet page with the naked eye
- This type of paper is new to the marketplace, so it is still unknown how much the paper is affected by yellowing and deterioration
Identifying High-Quality Bible Paper
In light of this information, the question naturally arises, “How will I know high-quality Bible paper when I see it?”
Well, there’s no magic formula, but it comes down to a variety of factors and your preferences. The next time you’re looking for high-quality paper, consider this checklist:
Opacity: Minimal or significant show-through?
PPI: What is the paper’s numerical rating? Does the thickness make the Bible too heavy and/or bulky?
Formation: Hold a page up to a light and look for splotches or inconsistent amounts of light being allowed through the page.
Think of “high-quality Bible paper” as being on a spectrum rather than in a static, black-and-white category. There are some widely accepted nonnegotiables (opacity, PPI, and brightness), but the rest comes down to subjective preference (whiteness, creaminess, texture, etc.). In the end, “high-quality” is in the eye of the beholder.