Material needed

~Picture 2~

Start with a 10mm 'margin' (shown in solid red) this is where I take all the other measurements from – 10mm allows enough room for a sewing 'tab' and provides known straight lines with a known right angle and as sections outside this margin are tabs used for sewing, accuracy is not as important here.

So please note that in accordance with this, all measurements shown on the diagram are taken from the margin.

While all measurements shown can be drawn out on a grid I have only shown a few Grid lines (red dotted lines) as otherwise the diagram would have become too busy.

Draw out the lines shown in black in the diagram above (I used navy blue Nylon so I drew the pattern using a yellow pencil) – note if you do not want a top handle then you do not need to bother with the following:

~Picture 3~
 
Lay the material over the felt and using a straight stitch (i.e. not a zigzag) sew along the marked out lines (shown in black on the previous diagrams) this should result in a pattern something like:

~Picture 4 ~

I found the felt did not sit perfectly flat, however it will stretch so try and keep it as flat as possible but do not be too concerned if the material does not end up perfectly flat
This stitching serves two purposes:

1. it keeps the material and felt together during assembly

2. the stitching is visible from the both sides providing a reference when the cover is being stitched together.

cut the material (and felt) about 1 centimetre (or 0.4 inch) around the stitching (note do not cut out the handle yet) this should give you a piece looking something like this:

~Picture 5~

cut notches out at each corner in as far as the stitching:

~Picture 6 --> Picture 7~
 
Cut a hole through the material in the middle of the handle but leaving about 2 cm (4/5ths of an Inch) between the hole and the stitching for the handle - something like this:

~Picture 8 --> Picture 9 ~

 From the rear, trim the felt as close as you can get to the stitched seam around the handle:

~Picture 10 --> Picture 11~

Cut Diagonally from the corners of the centre hole out to the corners of the seam

~Picture 12~
 

Fold these four tabs in and Sew them in place using a zigzag stitch around the hole. Although the Rip stop Cordura I used is pretty tough, it is still a good idea to provide extra reinforcement for the corners by running an additional seam diagonally across each one:

~Picture 13 --> Picture 14~

 

The next tip may be well known to sewing machine aficionados, but as a complete novice I was pleased to find that when I set the sewing machine to give me a tight zigzag stitch with one side of the zigzag off the edge of the hole the machine provided a nice, neat, reinforced seam (similar to around button holes) around the edge of the handle like this:

~Picture 15--> Picture 16~
 

Take the side piece and sew it to the felt by running a straight seam:
10mm from one edge, 10mm from the top and 15mm from the bottom

~Picture 17~ 

trim the felt along the seam 15mm from the bottom (i.e. the light blue strip in the diagram above)

~Picture 18--> Picture 19~
 

fold this strip over and sew in place with a zigzag seam – same as we did for the handle.

This will give a nice neat edge to the bottom of the cover.

You will note that the width of this material should be closer to 1165 rather than the measurement of 1135 in the diagram above – being a pessimist I chose not trim it to length until I had finished.

Next place this piece felt side down on a flat surface and line up the other piece (felt side up) as shown in this picture:

~Picture 20~
 

note the Tab on the top piece aligns with the seam sewn down the right hand side of the Side piece NOT the edge of the Side piece.

~Picture 21~
 

The dotted red line shows where the seam on the side piece is and is shown here for reference only

Now sew the two pieces together – I used a straight stitch along the reference seam with a zigzag stitch along the tab to provide more strength – note ONLY stitch along the Tab.

~Picture 22~
 

When you have completed that seam pull the top piece around so the next edge lines up with the top of the side piece:

~Picture 23~
 
Note you will need to pull this tight to ensure there is no gap between the adjacent tabs – as the layers of material and felt are now getting quite thick this will require some effort.

~Picture 24~
 
Sew the next tab down, turn the top piece around and repeat until all 10 tabs are sewn to the top of the side piece.

Finally sew the ends of the Side piece together and trim to length – this should leave you with something looking like: