Help and Tips for Dividing & Marking Mari

Dividing the mari is traditionally done by using a thin strip of paper and relational geometry. Relational geometry means that all distances on the mari are described "in relation to"  - that is, compared to - an already established standard. In dividing and marking a Temari, that means you pin the end of a thin (about 1/8" or 3mm) paper strip anywhere on the dodai mari. This becomes your North Pole (which is always denoted with a white pin). Everything else, every other point, line, etc., will be relative (compared) to this point. For this reason, once the NP is "pinned", you do not remove the pin until the division is complete. Hard as we try, no one can make a perfectly round mari, so even the NP is relative to its position on the mari, and will absorb the little ripples on the mari surface as you progress. But, a different NP on the same mari will create different ripples to adjust to, so once you start it's required to keep going from that point. If you change NP points even on the same ball, you need a new paper strip; nor can you re-use a strip on a different mari.

While strips can be cut by hand, the most accurate and efficient source is quilling strips. They can be found in most craft stores or online. These are already pre-cut, straight and true (which is important), and thin, about 1/8 wide - and long (a medium to larger temari can outreach a strip cut from a standard sheet of paper, and taping together is not a great idea because of accuracy). Too wide a strip will make pinning difficult and result in errors in the division and marking, as will strips that are not straight. Quilling paper is also a bit more durable and flexible compared to regular papers. One package costs about \$2.00US and will go a very long way.

While any pins can be used, it is advisable to have a supply reserved for temari making, rather than interchanging with those you use for sewing; the pins will take some wear from being inserted into mari. Most useful are small colored-head pins, thin shaft, in the standard assortment of white, black, red, green, blue and yellow. They do not need to be any more than regular length - indeed, longer ones generally only tend to snarl threads while you are stitching. Similarly, larger heads will only do the same. Be sure to get regular point, not ball-point (used for knit fabrics), since they are not as sharp and will not insert cleanly.

The strip is wrapped around the full circumference of the mari, brought back to the NP pin, and cut to exact length (remember to always target the PIN, not the end of the strip, at all times). The strip is now the established standard for the circumference of the mari. The place where it is pinned to the mari is the NP, so by folding the strip in half and placing a small mark (either pencil mark, or snipping a tiny notch in the strip), and replacing the strip around the ball, the 1/2 mark becomes the south pole, and a pin ( by convention, the SP is always a black pin) is placed in the mari. to double check, allow the strip to rotate freely around the NP, and "spin" it to another latitude line, and re-measure to the SP. It should be very close if not exact (within 1-3mm is fine). If not, adjust it. Repeat this one more time, again adjusting if needed. This will average out the best south pole. If by now (3-4 adjustments), no matter from where you run the strip from NP to SP, it's not within 1-3mm, the ball is not round. It's time to start over (seriously, it will just be an exercise in frustration to continue on a non-round enough ball).  Either choose a different dodai mari and begin again, or re-wrap the one you are using to round it off some more.

With the north and south poles established, the equator becomes easy: fold the strip in half again (that is, into quarters, and remember it is still pinned to the NP), and mark the new folds (there will be 2, equidistant from the first one that gave you the SP). Run the strip from NP to the 1/4 mark and place a pin. Spin the strip around the NP a short distance and repeat. Continue this until you have placed about 8 pins (they are not equally spaced at this time) around the mid-line of the mari. This pin line establishes the equator. With another pin at the ready, carefully remove the pin at the NP and slide the "new" one into the exact same place as you slide the first one out, releasing the paper strip. Depending on the number of simple divisions needed, divide the length of the strip into the needed number. This can be done by folding the strip if the required number is a multiple of 4. Other methods, including measuring the strip length and dividing with a calculator (for example, to build a Simple 15, but remember to use mm measurements or it gets messy)  to find the segment distances, and placing pencil marks/notches on the strip. When notching the strip, be sure to always snip all notches on the SAME edge of the strip, and to keep them tiny both in terms of width and depth. The pinhole in the strip from the NP is aligned right next to one of the mid-line pins, and a new (not white or black) pin is inserted into the NP hole. Wrap the strip around the mid-line pins, aligning the edge of the strip to the pins. If using notches, the open edge should facing the pin, with the bottom of the notch pointing away from the pins. Adjust the pins to align with each notch.

When inserting pins, it is important to keep them vertical and straight. The shaft of the pin has volume, and if placed on an angle, collectively there can be significant error introduced into the division and marking if the pins are not straight. This can make a difference in the evenness and accuracy of the division and marking. This is because temari work is on a sphere and the laws of spherical geometry apply.  Spherical geometry is much different than linear (flat) geometry, the most important thing being that errors "grow". There are laws of math to describe why, but we don't need to expand upon them. What is important is that you remember it happens, so even small errors need to be avoided or corrected. A little error made "here" expands greatly "over there" (where as in linear, flat geometry, an error "here" is the same as "there").

When placing pins along the marking strip, be sure that you are consistent. Some people keep to the edge of the strip, placing the pin in the center of the wide edge of the notch along the edge of the strip. Others place their pins into the v of the notch, rather than the edge. Whichever you choose, be sure to stay with that one otherwise you will introduce errors. Don't pull the marking strip out of shape as you lay it on the mari, especially if you cut larger notches (smaller ones will usually be more accurate). Alternately, some people will use only the fold in the strip as the placement indicator rather than cutting a notch. Some people put a pencil mark on the fold.  Others will cut only a slit rather than a notch. The point is that there are various ways to get to the needed result. Choose what is comfortable for you and what works for you.

When you have placed the pins, a quick way to check for symmetry is to hold it by the north and south pole pins and  gently spin the mari. You should not see "wobble" along the pin paths.  After the pins are placed, the marking threads can be laid down following the pin placements. Do not discard the strip after creating the simple division, since you may need to use it in a further division such as a Combination, or to set stitching points in the pattern you are going to work. It's helpful to pin the strip to the mari, especially if you are marking several at a time, to be sure that they remain paired.