DYMO's user guide for the LabelWriter 550, 550 Turbo and 5XL says to use only authentic DYMO labels, and that damage from third-party labels isn't covered by the warranty. That makes label choice simple but narrow.
Rules of thumb
The 5XL takes DYMO LW media up to 4.53 in wide, including 1744907 4 × 6 in labels.
The 550 takes DYMO LW media up to 2.44 in wide, so 4 × 6 in labels don't fit.
Third-party “DYMO-compatible” rolls are generally marked as not for the 5XL.
Fit by printer
Confirmed = named by the label or printer maker. Conditional = specs match or an accessory is required. Unknown is never treated as compatible.
Brother QL-1110NWB product page(Brother USA, manufacturer product page; checked September 27, 2026) — Page lists older OS versions; current drivers are on Brother support.
Brother QL-1100 product page(Brother USA, manufacturer product page; checked September 27, 2026) — Page lists older OS versions.