After you have made your strip of lace long enough for this month’s project, Lace-Edged Doily, the temporary crochet chain of the provisional cast on used to start the lace edging can be removed as the first step of preparing for the invisible join.
The pattern instructions say to “Release cast on sts from waste thread and place them on your loose knitting needle … ”
I hope that you have already taken advantage of previously posted tips & techniques for originally making your temporary crochet chain, as these help make the job of later removing the chain go more easily and smoothly:
1. Selecting a waste thread
2. Working a few extra chain stitches beyond the number of stitches needed for your cast on

Pull a loop of lace thread through the bumps on the back side of a crochet chain for each cast on stitch required
3. Picking up into the bump on the back side of the chain stitch, not the heart-shaped part
After working your lace strip to the length needed, when you are ready to remove the temporary crochet chain, proceed as follows:
4. To start “unzipping” the chain easily, loosen the bump-side loop at the end of the extra chain stitches and pull out the waste thread tail.
5. Slowly pull on the waste thread tail so that each extra chain stitch is undone, then stop pulling.
6. With the knitting needle onto which you will be placing the stitches of the provisional cast on row, insert the needle tip through the “live” stitch being temporarily held by the next chain stitch.
Tip 6a. Take care not to split the thread of either the live stitch or the chain stitch.
Tip 6b. Work over a table or pillow in your lap, so that your needle can be supported when you need to use your hand to continue to unzip the chain.
7. After the live cast on stitch is securely held on your needle, slowly pull on the waste thread tail again so that ONLY the chain stitch holding the secured cast on stitch is undone.
Repeat steps 6 and 7 until all provisional cast on stitches have been placed on the knitting needle.
Notice that this method does not involve cutting or otherwise damaging the so-called waste thread. Thus, it really is not “waste”, but rather you can use again for a future project that requires a provisional cast on of a similar number of stitches!
I hope this helps you enjoy peace of mind and without dropped stitches, tears or frustrations as you progress along the way in completing your Lace-edged Doily.