You can make balls from strips of any material that has the right combination of stiffness and flexibility, like stiffened fabric, chair cane (soak it first), plastic sheet or the veneer strips meant for edging furniture. My next task will be to weave a lampshade from some plastic post-factory waste strips that are (I think) polypropylene and came from the Leeds Scrap Warehouse.
The weaving process is a little tricky, so I suggest you start by making a ball from paper to get used to the technique. An A4 sheet (297 mm x 210 mm) will make a ball that is about 85 mm diameter, because each 297 mm long strip goes right round the circumference. Therefore, allowing 7 mm for the overlap where the ends meet, d=290/π or 92 mm. (It will be a little smaller because some of the length of the strip is taken up in weaving in and out.)
Balls like this made from plain coloured paper or Christmas wrapping paper would make pretty tree decorations. You can make a bigger ball if you like, but don’t try a smaller one until you know what you’re doing, it will be too fiddly.
Whatever size of ball you want to make, the strips you use should have an aspect ratio (width:length) of somewhere around about 1:35 or 1:40. You can use a bigger ratio (eg. 1:50) to produce a more open ball, but a ratio that is much less than 1:35 won’t work. Note that the dimensions for an A4 paper ball are different, because each strip is folded lengthwise into 3 and only then is the ratio about 1:40. If you use something that is stiffer than ordinary copier paper, then it will not be necessary to fold it into 3, or possibly not even into 2. Making a small paper ball as a test piece before trying anything more complicated will help you to understand what degree of stiffness is required – too stiff and it will be impossible to weave, too floppy and the ball will not hold its shape.
Fabric can be stiffened by painting on diluted PVA (a ratio of 4 parts water to 1 of PVA is suitable) or using spray starch. If using PVA, allow it to dry and then paint on another coat if it isn’t stiff enough. Cut the strips after stiffening to minimise fraying.
Materials for an 85mm diameter paper ball
A sheet of A4 paper (approx. 80g/m2 – ordinary printer/copier paper) or a larger sheet of paper sufficient to cut 10 strips that are each 297 mm long by 21 mm wide
10 or so paperclips
Masking tape or sellotape
A pencil and a ruler
Scissors or a craft knife or roller cutter and a cutting mat
Step 1: Cutting and folding the paper strips
Cut the sheet of A4 paper lengthwise into 10 equal strips measuring 297 mm x 21 mm. Mark the strips first with the ruler and pencil and then cut them up with scissors, or use a craft knife or roller-cutter in conjunction with a steel ruler and cutting mat. You don’t need to be super-accurate.
Fold each strip lengthwise twice. Do this by first folding in one long edge by a third (resulting in a strip 2/3 of its original width) and then folding in the other long edge to meet the first fold. This will produce a triple layer strip that is 7-8mm wide.
Before weaving the strips, curve each one a little by pulling it round the edge of a curved table top or some other suitable edge. Do this with the open flap side downwards so that it ends up on the inside of the curve. Also, check that one end of the folded strip will fit into the other end – re-fold the last 7-8mm or so of one end to make it a bit narrower, or the other end to make its “pocket” a bit wider, if necessary.
Step 2: Starting to weave the strips
When you come to lay down each of the strips you are using, do it so that they curve upwards. Looking at the sequence of photos you will see two things: 1. each strip must weave through the others, alternately over and under each of them, and 2. once the fifth strip is in place and the preceding ones have been woven up and under it and each other as necessary, you should end up with a regular pentagon-shaped hole in the centre. Slide the strips together to make the pentagon as small as it can be.
The next stage brings in the remaining five strips. Again, each one must weave alternately over and under the other strips that it crosses. If you follow the path of each strip from one end to the other, it should go over-under-over-under (or under-over-under-over), never under-over-over-under, for example. But don’t worry too much about where the strips cross near their ends for now, as the under-overs may change as the weaving progresses and additional strips are woven in at any given junction. You are working outwards from the central pentagon, so concentrate on getting the junctions that surround it right, then the next ring of junctions, and so on.
Each of the five new strips should end up approximately parallel to one of the five original strips – see picture 9. That will create 5 (irregular) hexagon-shaped holes surrounding the central pentagon. I have used the strips in coloured pairs so that the parallel lines can be seen.
Step 3: Creating the ball shape
Step 4: Finishing off
A final refinement is to slide each strip around to hide its joint under another strip.
Now you know how to weave these balls, have a go with different materials like rattan, the paper ribbon that is sold for wrapping presents, cable ties, the tough pastic binding strip that comes round parcels or birch bark.