The mods will lock it if and when one of them decides to do so. Many threads are allowed to run over 100. Conversely, you can click on notify and ask that the thread be locked. Once locked, no one can post to it.
When starting a new thread give everyone a quick recap of your stitch in the first post, and add a link to the previous thread for people to click on in case they want to look back.
M: A really long time. Crisis: 5 years. She's still worth it.
Life is never made unbearable by circumstances, but only by lack of meaning and purpose. -Viktor Frankl
