Clamshell Box Part 4: Lining the Clamshell Interior

Once the clamshell basic case is complete, adding a soft interior liner protects the book cover decorative elements such as onlays and dimensional covers. The liner also protects the spine of the fine binding.

1. Before working on the interior, allow the clamshell case to dry under weight for about 24 hours, depending on the environment humidity.
2. Open the clamshell case and measure the width of space between the two tray open edges. Measure the length of space between the small base tray’s 2 short sides.
3. Cut a bookcloth spine strip with the exact length measurement of the smaller base tray and the width measurement + 3/4″ for both sides to overlap the edges of the trays.
4. Apply PVA glue to the spine strip’s backing. Position the strip inside the smaller base tray by 3/4″ between the short sides at the open edge of the base tray. Lightly lay the strip over the interior spine panel and center between the short sides of the larger cover tray open edge by about 3/4″. Don’t press the strip dow yet.
5. Start at the small base tray side, smoothing the bookcloth on the tray edge. Use the bone folder to crease into the hinge indention, creating a bond with the hinge cloth underneath.
6. Smooth the bookcloth over the spine panel and again use the bone folder to crease the second hinge indention. Finally, smooth the spine strip over by 3/4″ on the larger cover tray open edge between the short sides. Notice on the larger cover tray there will be a board thickness gap between the top and bottom edge of the spine strip and the tray sides – that is normal. The tray side turn-ins will cover the gap distance.
7. Select a wool felt or suede-like material for the interior pad linings, preferably with a paper backing to handle the glue without leaking to the fabric surface. Select a millboard for the pad’s base that is half the thickness of the tray millboard. The pad lining will be wrapped around the thinner millboard. The softer material will prevent the fine binding from sliding in the case.
8. Cut a millboard panel to fit inside the base of the smaller base tray first. The width and length of pad panel must allow space for the material to wrap around the panel. So cut the pad panel to be an 1/8″ shorter on the length and width. Note: that the pad panels will be positioned in the center of the trays. Be sure the “grain” of the millboard is on the length of all the cut pad panels.
9. Cut the millboard spine pad panel to be the same length as the smaller base tray. Cut the spine pad panel width to be about 1/2″ less than the clamshell hinge spine panel. It will be centered on the spine piece.
10. Cut the millboard pad panel for the larger cover tray to the same size as smaller base tray pad panel. It will also be centered on the tray. 

Lining the spine pad panel

1. Lay the fine binding in the smaller base tray to check for fit.
2. Cut the lining material for the spine pad panel 3/4″ larger on all 4 sides of the spine pad panel. Rough miter the corners but leave enough fabric to cover the millboard panel corners. Note: If the lining fabric doesn’t have a paper backing, a glue test on the selected lining material is important. Apply PVA glue to the back of the material. If it leaks through to the front surface of the fabric, select a different material for the lining.
3. Glue the 3/4″ area of the millboard panel edges. Fold the fabric turn-ins, pinching the corners in a 45-degree miter.
4. Miter cut the corners of the spine piece. Smooth the edges and corners with the bonefolder.
5. Set aside to dry.

Lining the tray pad panels

1. Cut the lining material 3/4″ larger on all 4 sides of the small base and cover tray interior pads.
2. Glue the 3/4″ area of the millboard panel edges. Fold the fabric turn-ins, pinching the corners in a 45-degree miter.
3. Miter cut the corners of the spine piece. Apply more PVA glue if needed to the corners.

Interior lining panel pads preparation

1. Tuck in the fabric at the corners.
2. Use the bone folder to smooth the corners flat.
3. Apply PVA glue to the first covered panel – the small base tray pad. Avoid getting glue too close to the edges. Glue is only needed on about two-thirds of the turn-ins and the millboard back.

Finishing the case

1. Center the fabric covered pad into the small base tray interior. Press into place.
2. Apply glue to the fabric covered spine pad. Align the pad’s top and bottom edges with the first base tray pad’s top and bottom edges. Center the spine pad width on the hinge spine piece. Press into place.
3. Apply glue to the fabric covered cover tray pad. Align the pad’s top and bottom edges with the spine pad’s top and bottom edges. Center the pad width on the large cover tray piece. Press into place.
4. Leave the clamshell case open and place weights in the interior lined pads. Set aside and allow to dry for a minimum of 24 to 48 hours depending on the humidity.
5. Test type treatment for the fine binding title. Print out best 4 samples. Make a selection.
6. Cut thin, 1 mm chip board to fit on the spine width and cover with a decorative paper. Determine how much of border is wanted on the title panel. Cut the selected type title to fit on the title panel. Glue the title panel to the clamshell case’s spine.