What is yapp?
Yapp refers to the length of the leather used for a Bible’s cover, for the purpose of protecting the text block. The edges of the front and rear covers extend beyond the front and back of the Bible, and some can fold over the edge of the text-block to protect it. Named for the 19th Century British book binder William Yapp who introduced the technique for pocket sized Bibles, this form of binding is still quite common for contemporary Bibles.
Yapp bindings can be divided into full-yapp, semi-yapp, and standard-yapp. Our standard-yapp extends just beyond the edge of the text block (3/8”). A semi-yapp binding has the front and rear material extending partially, but not fully, over the text-block (9/16”). A full-yapp binding would have the extended cover material covering the text-block edges entirely, possibly overlapping each other.
Yapp is the single most debated aspect of a Bible’s construction. People are clearly divided within the preference of the three different yapp lengths. One of the appealing factors when people decide to have a custom Bible rebind done, is that you get to choose which style your Bible rebind will have.
We don’t charge extra for semi-yapp, or full-yapp. However, there are some things you should consider while deciding which yapp is best for you, and your Bible.
Bible text-blocks come in a variety of sizes. A text-block’s thickness should be considered when you’re deciding what type of yapp you want with your Bible’s rebind. A thick text-block may not be a reasonable choice for a full-yapp. A thin text-block will create problems with semi-yapps. Let me try to explain.
Starting with the small, thinner text-blocks, lets consider what happens when you ask for a semi-yapp on a 1”, or thinner, thinline Bible. Keep in mind a semi-yapp is a 9/16” extension beyond the end of the text-block. Once the cover’s semi-yapp is trained and rolled over the edge of the text-block, the yapp, front and rear, will touch. The semi-yapp will automatically become a full-yapp on a thinline Bible.You really only have two choices with many thinline Bibles. Standard-yapp, and full-yapp. (You can conceivably train the standard-yapp (3/8”) to roll over the text-block edges, but that’s an extreme option in my opinion.)
Now, what about thick Bible text-blocks? I personally advise leaving full-apps to Bible text-blocks that are 1.75” thick, or less. The reason I say this is precisely related to the amount of leather you’ll be dealing with every time you open your Bible. I’m currently working on a Study Bible that is 2.25” thick. That’s in excess of 1” of extra leather on the front and back cover for a full-yapp.
The size of your Bible matters when you’re deciding what you want for yapp size. Yapp is there to protect everything on the inside of your Bible, but your Bible’s size will ultimately decide how happy you’ll be with which type of yapp you decide upon.
Our standard-yapp extends beyond the text block (3/8”), representing the typical publisher-produced Bible style used for the past century.
A semi-yapp binding has the front and rear material extending partially over the text-block (9/16”). This style offers extra protection for the Bible’s text-block without adding significant bulk.
A full-yapp binding features extended cover material that covers and overlaps the text-block edges, offering maximum protection for your Bible’s text block and echoing the style of 1800s Bibles.