On the test sail, I started sewing the bolt rope onto the back side of the sail, but gave up on that approach since the stitching look overly large for the scale of the model. Instead, the bolt ropes will be glued on. Starting with the crojack sail, the bolt rope is attached in the following manner, and it looks good at 1:100 scale. Wolfram zu Mondfeld's
Historic Ship Models provides information for British ships on the diameters of the bolt rope for different sails so you can choose the correct line size. The rope on the head were about twice the diameter on the rope used on the leeches and foot of a square sail. On the course sails, bolt ropes were about half the diameter of the stays use to support the lower mast. Topsail and topgallant sail bolt ropes were 1/4 the diameter of the topmast stay line, and royal sail bolt ropes were 1/5 of that diameter. The lateen sail has the same size bolt rope all the way round the sail. I used these rules as a guide in choosing the line size for the bolt ropes.
A length of bolt rope from 0.25mm line was cut long enough to be placed at the leeches and foot of the sail. 0.45mm line will be used for the head of the sail as a separate piece. Masking tape is used to hold the sail and the line on the cutting board. You start at the upper corner of the leech, and will run the line across the foot, and back up the other leech side while forming clews and cringles along the way.
Here is what the bolt rope looks like when it is sewn onto the test sail. The stitching stood out far too much. This method is okay for larger models, but not one this small, so it was abandoned.
The following shows how to attach the bolt rope to the crojack sail. The line and sail are taped down lightly, then PVA glued diluted weakly with some water is brush along the edge of the sail and the bolt rope. A heat gun set on low heat setting is used to quickly set the glue and dry it.
The heat gun anchors the rope in place by drying the glue.
A length of thin thread is used to seize a loop at the lower corner of the sail to form the clew loop. After the seize is drawn tight, the bolt rope is drawn until the clew loop is the correct size.
Here is the finished clew from the front side of the sail after the PVA is dried to firmly attach it to the sail corner.
Continue gluing the bolt rope around the sail and drying the glue with the heat gun.
Form the second clew loop just as you did on the first one and continue attaching the bolt rope up the other leech side of the sail.
At the top of the sail, the heavier bolt rope used for the head is passed through and glued to the leech bolt rope where the bottom of the earring cringle is supposed to be.
The head bolt rope is then passed through the leech bolt rope at the top edge of the sail, and pulled through until the earring cringle is the same size.
Then the earrings has diluted PVA applied to secure it to the sail.
The end of the leech bolt rope and starting end of the head bolt rope are trimmed off, leaving a nice earring cringle at the corner of the sail, here viewed from the front side of the sail.
Attach the head rope along the top of the sail, thread it through the leech bolt rope, then back round to form the second earring cringle by passing it once more through the leech rope, glue it all down with diluted PVA, trim the bitter ends, and you're done! For courses, you can add cringles on the leeches and foot using the same method as the earring cringles. They should be strong enough to support the sail and rigging unless you get careless and catch and tear them.
Oh well. I'll get it right on the next ship model. 
