Just as a reminder...
Basic (closed) sprang:
  1. 2F/B (F/B) F/2B
  2. F/B
Open sprang:
  1. 2F/2B
  2. F/B
  3. F/B (2F/2B) F/B
  4. F/B
Patterns are read from right to left. If this is confusing, read basic sprang.

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The basic and open sprang techniques can be combined to make lacy patterns. Diagonal patterns are best, since the rows of holes are staggered. These directions are for a diamond figure of open holes on a tight background. The sample warp has 20 strands (10 front, 10 back), and the diamond looks like this:

 O O 
 O O 

  1. 2F/B (F/B) F/2B
  2. F/B
  3. 2F/B F/B F/B F/2B 2F/B F/B F/B F/2B
  4. F/B
  5. 2F/B F/B F/2B 2F/2B 2F/B F/B F/2B
  6. F/B
  7. 2F/B F/2B 2F/2B 2F/2B 2F/B F/2B
  8. F/B
  9. 2F/B F/B F/2B 2F/2B 2F/B F/B F/2B
  10. F/B
  11. 2F/B F/B F/B F/2B 2F/B F/B F/B F/2B
  12. F/B
  13. 2F/B (F/B) F/2B
  14. F/B
All the pattern changes are done in odd-numbered rows. I think of my sprang as growing from the top down, so this explanation reflects that. Holes can be thought of as in columns which skip every other row.

Row 3: To start a hole, treat the warp as two separate sections of basic sprang, ending one section before starting the next. (To start with more than one hole, add (2F/2B) for as many holes as you want.)

Row 5: To add a hole directly to the right of an existing hole, and in the row below, continue normally until there are 5 threads (including top and bottom) left before the hole. Then sprang 2F/B to end the section and add a new hole.

To close a single hole temporarily (while keeping its column), close the hole with 2F/2B.

To add a new hole to the left of an existing hole, after closing the hole, begin the next section of basic sprang with F/2B.

Row 7: Add a new hole to the right, temporarily close the previous holes, add a new hole to the left.

Row 9: Close the rightmost column of holes permanently by continuing the basic sprang until only one thread remains before the hole, then close the hole with 2F/B. Keep the central two holes by closing them with 2F/2B.

Close the left hole with a F/2B to remove the column permanently.

Row 11: Close the right and left columns of holes, keeping the middle one.

Row 13: Return to basic sprang, closing the last hole.

A wide variety of diagonal patterns can be made, as in this detail from a sprang baldric:

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