Turks Head Knots and their expanded versions make great decorative finishers to many projects, and can help protect and cover other bits of knotwork.
A working knowledge of knotting terms is assumed.
The three methods shown: "Standard expansion" which results in a THK with two extra leads and two extra bights, still in an Over 1 Under 1 pattern. "Spanish Ring Knot style expansion" which results in a THK with two extra leads and an Over 2 Under 2 pattern. "Doubling" which results in a THK with no added leads or bights and an Over 2 Under 2 pattern.
For the purposes of this tutorial all knots will be tied on a clear glass bottle with blue paracord, with a red sleeve to show the last tuck made and position of the working end.
The three methods of expansion can be combined. You can do standard expansion to get a 5 lead knot, then do it again for 7 leads, then Spanish Ring style expansion to change the pattern, then double (or triple) the knot, or any other order. Experiment! Doubling is usually done last, since it tends to look best as a finishing step.
Step 1: Tying a 3-lead Turks Head Knot
Wrap around the bottle again, coming up and over the second wrap to the right.
Tuck the working end under the standing lead (under 1) and over the second lead (under 1) to the left.
Cross the standing lead under the second lead, this will form a small loop.
Pass the working end under the second lead and over the standing lead.
Continue this process, passing the working end under 1 and over 1, swapping the standing and second leads to make a loop, and passing the working end under 1 over 1 until you return to the start of the knot, on the same side as the standing end.
You will have a 3-lead Turks Head with an over 1 under 1 pattern, and a number of bights dependent on the size of your core and how tightly you tied the knot.
Step 2: Standard Expansion
Begin by taking the working lead Under 1 Over 1, to the rear of the standing lead.
Cross Over the standing lead, then U1 O1, keeping to the rear of the standing lead.
Repeat this process until you have gone around the knot once.
When you return to the start of the knot you should see the standing lead passing U1 O1 U1, with the leads it passes having O2 U2 O2 patterns visible, respectively.
Take the working end O1, U1, O1 to the right. This will eliminate the O2 and U2 crossings seen before. This also still follows the standing lead to the rear.
Continue this process around the knot, going U1 O1 U1 O1 each time, eliminating O2 ard U2 crossings.
When you return to the beginning you will have a 5-lead knot with an O1U1 pattern throughout.
Step 3: Spanish Ring Knot Style Expansion
Pass over the standing end, and follow it in front (U1 O2 again)
When you return to the start of the knot the working end will be on the opposite side from the standing end.
Continuing to follow in front of the standing lead, go O2 U2 O2.
When you return to the start of the knot again a 5-lead knot with an O2U2 pattern will result.
Step 4: Doubling
Keep doing this until your THK has two passes of cord.
This will add 3 leads and no bights to the knot, and will result in an O2U2 pattern.