I am presently writing up the pattern.
This is my second Iolanthe (pronounced “eye-oh-LANTH-ee”). See the first version (short sleeved) here. I’d planned to make long sleeves, but the purple color & merino-silk blend seemed so spring-like that I went with 3/4 sleeves instead--I’ll wear this a lot in April:)

The yarn is a dream to work with--it drapes beautifully at 6 spi.

It was a pain to blend a new skein of yarn for the sleeves--I’d saved out some of the first skein (that I’d cast on with) to use for part of the sleeves (and alternate with the new skein to blend the two). But the end of the first skein (that I’d cast on with) was quite different from the beginning of the same skein. So I luckily had another skein that was a bit more variegated (like the beginning of the first skein) and used it to alternate.