First, the book is measured. If you are using a MEASUREpHASE, take all three measurements as usual (length, width, and thickness.)

If you are using a ruler, take the length and width measurements as shown. You can either dispense with taking the thickness measurement or take it by placing the book between two pieces of board, by means similar to the method shown here.

Two pieces of 20 point folder stock are cut.

The width of one piece is equal to W, the book's width. (This is the narrower piece in the image; we will call it "Piece A.")

The width of the other piece is equal to L, the length of the book.

Grain orientation of both pieces is grain short.

As can be seen, the direction we're headed is toward a structure with a center panel (the overlap) and four flaps. The minimum lengths of the flaps are given in the illustration. (Again, these are the minimum measurements; excessive is fine here.)

Whether or not you measured the thickness of the book in the previous step, an approximate (T) measurement will do for now, as long as the total isn't too small. For your final measurement, you will use the instructions shown a few steps ahead.

With "Piece A" on top, the two pieces are aligned squarely and glued together at the overlap, using PVA or PVA mixture. They are placed under weight, with the assistance of a flat board if necessary, and allowed to dry for an hour or so, or preferably overnight.

The two primary creases are made as shown, following the edges of "Piece A," using a bone folder.

The two primary creases are made in the other piece of folder stock, same as in the previous step. You will need to use the straight edge this time.

The secondary crease can now be marked on the first flap.

The flaps are marked successively; each is marked, creased, and folded over into closed position before the next one is marked. The reason for this is that the total thickness of the book and enclosure gains one board thickness with the closing of each flap, so the T measurement is accurate only for the first flap.

If you took the T measurement in the first step, simply transfer the measurement to the flap. If you did not measure, you can arrive at the T measurement as shown. Be careful not to mark on the book itself. (In fact, see the next slide before proceeding.)

Flaps are folded in the following order, relative to the orientation of the book:

1. bottom
2. top
3. right
4. left

It's a good idea to place a piece of paper over the book so it doesn't get pencil marks on it.

In the order previously given, the flaps are successively marked, creased, cut to length, and folded over into closed position.

The lengths of the top and bottom flaps (the ones folded over and pointing up, in the image) are not critical; they just need to be long enough that together they cover the full length of the book, plus a bit of overlap.

The lengths of the left and right flaps need to be such that they are flush when folded over, i.e., 1W from their outermost creases.

The enclosure is flipped over so that its outside is now facing up. The first three flaps (bottom, top, and right) are each trimmed to an arbitrary angle. The cut is made from the outermost crease of the flap. The flap that will close last (the left one) is left untrimmed for now.

The angle is duplicated on the flap's other side by means of using the scrap from the first cut as a template.

We now find the center of the left flap (see below) by situating a ruler diagonally and making a short mark near the middle. The ruler is aligned with the outermost crease at one end (upper left, in the image) and at the opposite corner of the flap.

Note: Remember that the enclosure has been flipped and that the outside is facing up. The instructions assume it has been flipped only horizontally, as indicated by the white arrow. This means it is horizontally reversed, that the flap we are calling the "left" one is on the right. We could have flipped the enclosure vertically too, to maintain left-right orientation, but that would potentially be even more confusing.

The opposing diagonal is marked.

The intersection of the two marks locates the center of the flap. It is from this point that we will be measuring in the next couple of steps.

We now proceed to measure for the tab that will tuck into the opposing flap and serve to keep the enclosure closed. The tab is square in shape. For books of average size, it is about 4 cm square. Its size can of course be adjusted, depending on the size of the book.

First, a mark is made 4 cm toward the outer edge of the flap from the center point. (Orientation is the same as in the previous image.)

Next, two marks are made, each 2 cm from the center point.

(Orientation is 90 degrees counter-clockwise, or a quarter-turn left, from the previous two images. For bearings, the mark near the top of the image is the one we made in the previous step.)

The flap is cut off at the first mark we made.

A line is marked parallel to the flap's edge and intersecting the center point (B in the image.) Two perpendicular lines are then marked at both the points 2cm from the center point (A in the image.)

Cuts are made at A, then B. When cutting the latter, you will naturally want to avoid cutting off the tab (yellow dotted line.)

Note: Normally the lines shown in this image are drawn more lightly with the pencil, lightly enough that they can later be erased. The lines are drawn heavily in the images for the sake of illustration.

The flap is cut accordingly, yielding a tab.

The tab works best if the corners are rounded. The radius is not critical; a penny is about right.

The corners are rounded using scissors.

The enclosure is folded into fully closed position. (It works well to do this with the book in it.) Marks are made as shown, in the corners at the base of the tab and in line with the width of the opposing (right) flap. The first two marks are for the slit into which the tab will tuck. As indicated by the red arrow, the cut is made a little longer than the width of the tab.

Note: The end of the top flap should fall just short of the mark on the right and thus be hidden from view by the two outermost (left and right) flaps. If it extends beyond this mark and is visible, it needs to be trimmed back.

The slit is cut in the right flap and the left flap is trimmed to angles on its outer edges as the other flaps were earlier.

The enclosure is flipped back over (the "left" flap is now back on the left) and the book is placed inside it.

The flaps are folded closed in the prescribed order, the tab is tucked into the slot, and the job is finished.