Polyester Film Book Jacket

The jacket is made from clear uncoated polyester film (Fig.2). It has end flaps that wrap around the cover, protecting the edges of the book and holding the jacket to the book.

Figure 2. Clear uncoated polyester film used to construct jacket.

• Bone folder
• Clear, uncoated polyester film, 4mil
• Cutting mat, self-healing or a piece of paper board
• Metal straightedge
• Scissors or utility knife
• Sponge

1. Measure the book as shown in figure 3.
   
   
   Figure 3. Height, width, and the thickness of the book are measured to determine the dimensions of the jacket.
   
   
2. Cut a piece of polyester film with a vertical dimension equal to 12/3 times the height of the book and a horizontal dimension four times the width of the book plus the thickness of the book.
3. Wrap the polyester film around the book so that the edges of the polyester are even with each other and the book is centered between the top and bottom of the polyester (Fig. 4).
   
   
   Figure 4. Position the book in the center of the polyester sheet.
   
   
4. Place the book on a clean work surface and open the polyester flat, being careful not to change the position of the book on the polyester film (Fig. 5).
5. Mark the position of the book on the polyester film by making dents with the point of a bone folder at the corners of the book and at both ends of the joint (Fig. 5).
   
   
   Figure 5. Mark the position of the book on the film at the arrows.
   
   
6. Wrap the polyester over the book again and turn the polyester and book over (Fig. 6). Repeat step five.
   
   
   Figure 6. The book is turned over to mark its position on the other half of the polyester film.
   
   
7. Using a straightedge and bone folder, crease the polyester straight across connecting the dents. Broken lines represent creases (Fig. 7). 
   
   Figure 7. Diagram of crease lines for book jacket.
   
   When creasing the polyester, place the straightedge on the film with its edge next to, but not covering, the two dents to be used as guides. Press the point of the bone folder into the polyester and pull it along the edge of the straightedge, creating a linear indentation. The straightedge should be held down firmly to prevent slippage. Without releasing the straight edge, reinforce the crease by inserting the bone folder beneath the polyester and rubbing it firmly against the straightedge (Fig. 8).
   
   
   Figure 8. Creases in the polyester film are reinforced by rubbing the exterior with a bone 
                   folder against a weighted metal straightedge.
8. At all “x” locations (Fig. 9), make a second crease parallel to the first, outside the first, and at a distance from the first equal to the thickness of the book cover.
   
   
   Figure 9. Second crease line is made parallel to the first at locations marked with an “x”.
   
   
9. Cut as shown in figure 10. Unbroken lines represent cuts.
   
   
   Figure 10. Polyester film is cutout to form book jacket.
10. Fold polyester film at all creases. Make folds sharp by burnishing them with a bone folder. Remember that closely spaced parallel folds need to be made at all “x” locations. After these have been made, shape them with fingers until both folds take on a 90º angle (Fig. 11). Dampening the finger tips slightly with a moist sponge will make this shaping of the folds easier.
    
    
    Figure 11. Folds are shaped with fingers to form a 90º angle.
    
    
11. Wrap the polyester film jacket around the book, tucking the end flaps inside the front and back covers.
12. Tuck the top and bottom flaps between the outer surface of the book cover and the polyester film (Fig. 1). The top and bottom flaps will be visible through the polyester film jacket.

Horton, R. 1991. Polyester film book jacket. Technical Leaflet: Bound Materials. Northeast Document Conservation Center, Andover, MA.