I've been working on Karey's Coronavirus Doily. It's a tat-a-long she has been releasing on her blog bit by bit HERE.
For Part 7, she says to use 2 shuttles so you can switch between them when the thread on one gets low. Two shuttles are also very useful to switch to the shuttle in the best position when moving between the inner and outer sides of the round.
With equal parts over-thinking the issue of keeping my variegated thread colors in sequence when reloading shuttles, wanting to minimize shuttle winding, and being a trouble-maker in general, I decided to use 1 shuttle and ball thread and make all the single rings as self-closing mock rings. Where there are 2 rings together, I worked regular rings, thinking that would have less chance of gapsosis. I figured shoelace ties to move the shuttle into the other position when necessary would not stand out next to the lock stitch chains. I wound several bobbins before starting, and it worked out right, so I never had to cut the ball thread to reload a shuttle.
Was it a good idea? I don't know. It saved me the time and effort of winding more bobbins, and that was good. I wondered if I was getting my SCMRs closed with consistent tension, and they probably aren't as tight as the regular rings. Is there too much color blip at the base of the SCMRs? I've already committed a few faults that won't bear up to microscopic examination, but from a few feet away, it looks pretty good.