Prusa XL Build Plate: The 365 mm Sheet, Thickness, and What Third-Party Plates Must Match
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The Prusa XL uses a steel sheet about 365 by 365 mm with the XL’s locating cut-outs, and no smaller Prusa sheet fits. At this size thick spring steel matters because a thin sheet bows between the segmented bed’s magnets. Buy a textured PEI sheet for most work and a smooth or satin sheet for glossy PLA; check that the listing names the XL.
The XL’s segmented heated bed is one of its features and one of its constraints: the sheet spans sixteen tiles, and it has to lie perfectly flat across all of them or the first layer varies from tile to tile. That makes sheet thickness and flatness the first thing to check on a replacement, ahead of the coating.
Where to buy
What to check
- Listed for the Prusa XL, about 365 by 365 mm with the XL locating cut-outs. Plates for other printers do not fit.
- Spring steel 0.5 mm or thicker so the plate stays flat on the magnets.
- Coating thickness stated; the XL is often used for large PETG and ASA parts that stress the coating across the whole sheet.
- Double-sided if you want smooth PEI as well as textured on one sheet.
Surface by material
- PLA: textured or smooth PEI, 55 to 60 °C.
- PETG: textured PEI, 70 to 80 °C; smooth PEI only with a glue-stick release layer.
- TPU: textured PEI, 40 to 50 °C.
- ABS and ASA: textured PEI at 95 to 105 °C with the XL enclosure fitted; smooth PEI with glue stick otherwise. Large parts on a large sheet show lifting first; use a brim.
The plates in the box
The upgraded XL PEI plate for carbon-fibre filament is a textured sheet sized for the XL; the two-pack of 365 by 365 mm double-sided XL plates gives textured and smooth with a spare. Both are third-party; the Prusa original sheets are sold through Prusa.
Swapping
- Wash the new plate with dish soap and hot water; dry; handle by the edges.
- Seat it against the rear stop on the magnetic bed.
- Run the printer’s auto-leveling so it measures the new plate; smooth and textured differ by a couple of tenths in Z.
- If the first layer will not stick, wash again before changing anything; see smooth versus textured.
FAQ
Do MK4 sheets fit the XL? No; far too small.
Why does my XL first layer vary across the bed? A bowed sheet or a tile calibration issue. Try a thicker sheet before re-calibrating tiles.
Glue for ABS on the XL? Not with the enclosure and a textured sheet; on the corners of very large parts as insurance.
LayerWalker
Print defect diagnosis, calibration procedures and parts that actually fit. Corrections welcome through the contact page.
