One of the things we touched on in the Repair & Restoration course was the basic structures we were likely to encounter. Knowing the difference between these structures is essential because if will ultimately affect how you repair the book and put it back together! You can’t turn a tight back into a groove back or mix the two, it just doesn’t work!

We covered three basic structures in the class: Groove Back, Tight Back and Tight Shoulder.

Groove Back

The groove back was already familiar to us because it is binding we have learned in level two. It is common in books from the late 19th century to early 20th century. Some of its distinguishing features are:

• Shoulders at 45° angle
• Groove on the outside
• End papers attach to the joint
• Sewing supports come under the end paper
• Cloth comes into spine
• Cloth attached to edge of board

Tight Back

The tight back is a structure we hadn’t encountered yet and likely weren’t going to encounter. The tight back is often used in leather binding. With leather binding no hollow tube is used, in cloth binding a hollow tube is used.  It was used in the mid 19th century and its distinguishing features are:

• Shoulders at 90°  
• End paper adhered to outside of the board
• Sewing supports come over and through the board
• Groove is on the inside

Tight Shoulder

The last structure we touched on was the tight shoulder. This is a case binding, with a cloth case. It is common in British and American bindings from 20s-40s. The distinguishing features are:

• Shoulders at 90°
• Cloth comes down a little jog into the board than back on to the board
• End paper comes onto the board

A few more things

Once again it’s important to remember these structures can’t be mixed (especially groove back and tight spine). The groove back is a case binding and a common problem with this is that it doesn’t support the textblock, so the text will eventually fall out.

Tips to tell Tight Back from Tight Shoulder:

Tight Back	Tight Shoulder
Shoulder Flat	Shoulder higher than spine
Sewing support on the outside & through the board	Sewing support comes on the inside

Another way of judging the structure is to be aware of the time period from which the book came.  Be aware though, the dates are only a guideline and not a firm thing.

Mechanical Time Chart:

	Tight Spine	Hollow Spine
Tight Joint	Early, up to 1860s	1850s-1900s
Groove Joint	——	20th C +

There you have it, a brief idea of three basic structures you’re likely to encounter and how to determine which structure the book as used. It’s very important to figure that out before you start any repair work. Once you start and the book is apart, you’ll have a lot of trouble figuring out what structure it was!

Until next time,