Next, let's look at the length of the laces. Steven's ligatures consisted of one black lace (approx 45" long, used to tie the right wrist to the right ankle) and one white lace (approx 34" long, used to tie the left wrist to the left ankle). Christopher's ligatures consisted of one black lace (approx 30" long, used to tie the right wrist to the right ankle) and one white lace (approx 34" long, used to tie the left wrist to the left ankle). Michael's laces are the most interesting because they were described by Lisa Sakevicius as "pieces of laces" instead of laces. This was apparently determined because both of Michael's ligatures had aiglets only on one end. Both of Michael's ligatures were black, the one on the right side measuring approximately 31" and the one on the left measuring approximately 29". All of these measurements can be verified by checking the evidence lists on Callahan's.
Now comes the interesting part. Since a lace was left in one of Christopher's shoes, where did the six laces used to hog tie the boys come from? First, IMO, it's obvious that the two white laces, both about 34" in length, came from Michael's shoes. I don't recall if the other lace from Christopher's shoe was measured. However, the two intact black laces were of differing lengths. I hadn't realized just how "different" in length the intact laces were. It has caused me to rethink my assessment of the ligatures.
Since Steven and Christopher had black laces in their shoes, but one of Christopher's laces was still in the shoe, I now think that the 30" lace was from the shoe of one boy and the 45" lace was from the shoe of the other boy. Either a 30" lace or a 45" lace (depending on the length of the lace remaining in Christopher's shoe) was broken and discarded by the killer. So, he improvised and removed one black lace from his own shoe (TH wore LA Gear knock-offs at the time, and one of Pam's sisters noticed one lace in one shoe missing shortly after the murders) and cut it into two pieces, creating the "pieces of laces" Sakevicius mentioned as Michael's bindings.
So, one black lace remained in one shoe. One black lace was broken and taken away from the scene by the killer. The other two black laces and both white laces were used to bind Steven and Christopher. Michael was bound with an adult lace, about 60" long, that was cut into two pieces.