Short answer: Standard rectangular cases don't fit the butterfly shape well and can bunch under your neck. Dedicated official covers are cut to match the contour.
Why this detail is listed under "honest details most reviews skip"
This genuinely useful, practical detail isn't obvious from the pillow's marketing photos alone — worth knowing before you assume any standard pillowcase will work.
A genuine reviewer account matching this exact tip
"Bought the official cover after reading the standard-pillowcase issue elsewhere — glad I did, fits perfectly and no bunching" — Lauren K.'s account directly reflects this specific, practical fix.
💡 Worth knowing: budget for the dedicated cover as part of your initial purchase, not an afterthought once bunching becomes a problem.
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