So you're working on a project, you run out of a thread, and your local needlework store says it's discontinued. What do you do?
1. The first thing I would do is ask them to call the supplier and see if there is any stock left. I recently ran into this issue with certain beads - although they were not listed on the supplier's website, when I called I found out they had a large stock and could supply them to my local shop if I asked for them to be ordered. It doesn't hurt to ask your shop to call the supplier - if a thread has been recently discontinued the supplier may still have some on hand.
2. Ask your stitching friends if they have it in their stash.
3. If you are on Facebook and in any needlework-related groups, post a request for the thread in the appropriate group. I've seen this work many times - either someone has it, or a shop will chime in that they have it in stock.
4. Even if your shop doesn't have it and the supplier is out, other shops may still have some. I try to give my business to local shops when I can - but in an emergency I would not hesitate to call around to find thread I needed to finish a project.
5. Sometimes there is a substitute. If you haven't started the areas on your project that require a discontinued thread, you may be able to find something else that is a close match in color and/or texture. Even if you've already stitched some areas, if they are not that close to unstitched areas needing the discontinued thread, a close match may work.
When all else fails, you may have to "unstitch" and find another thread to finish the project. This is very sad and frustrating - but if you really like the project it may be your only choice.
Be sure to purchase more than enough thread for your project, if it is available and you can afford it. I would rather have threads left over than not have enough. Be sure you understand your shop's thread return policy if you hope to be able to return unused threads for shop credit or a refund. This is a difficult area for shops because of dye lot changes, unknowns about where the threads have been kept (smoking home, pets?), age of threads being returned, and price changes. In my opinion, shops that allow thread returns, even if it's just for credit, are very generous - and those who choose not to do so have valid business reasons and should not be criticized for their policies.
If you have a stitch guide that calls for a discontinued thread, please have mercy on the stitch guide writer. None of the ones I know would deliberately call for a discontinued thread. We try to keep up and it is impossible to predict when a thread might be discontinued in the future. I also know at least two guild teachers who have encountered this on large projects they designed and planned to teach for a number of years, and they have gone to great lengths to find substitute threads and adjust their designs accordingly.
Related to this topic - Kreinik recently announced they were discontinuing a number of colors and have provided recommended substitutes. You can see the list on Janet Perry's blog here:
http://www.nuts-about-needlepoint.com/substitutions-for-discontinued-kreinik-threads/