{"id":75,"date":"2026-06-13T17:01:57","date_gmt":"2026-06-13T16:01:57","guid":{"rendered":"https:\/\/askthenozzle.com\/blog\/first-layer-adhesion-issues-with-petg-why-it-sticks-too-well-and-sometimes-not-at-all\/"},"modified":"2026-06-14T11:59:52","modified_gmt":"2026-06-14T10:59:52","slug":"first-layer-adhesion-issues-with-petg-why-it-sticks-too-well-and-sometimes-not-at-all","status":"publish","type":"post","link":"https:\/\/askthenozzle.com\/blog\/first-layer-adhesion-issues-with-petg-why-it-sticks-too-well-and-sometimes-not-at-all\/","title":{"rendered":"First Layer Adhesion Issues with PETG: Why It Sticks Too Well (and Sometimes Not at All)"},"content":{"rendered":"

If you’ve come from PLA, PETG breaks your instincts. The most common first layer adhesion issues with PETG<\/strong> aren’t about prints lifting off the bed \u2014 they’re about prints fusing to it so hard you chip the glass or tear the PEI coating getting them off. Then, on the same printer, the next print won’t stick at all. That paradox is exactly what trips people up, and it’s almost always down to two things: bed temperature sitting in the wrong place relative to the glass transition point, and a Z-offset copied straight from your PLA profile.<\/p>\n

This guide gives you the real physics and the exact numbers to fix it. No hype, no copied-and-pasted “increase your bed temp” advice \u2014 just what actually works for PETG.<\/p>\n

Why PETG First Layer Adhesion Behaves Differently<\/h2>\n

PETG has higher adhesion strength than PLA but needs more precision in bed preparation than ABS. Get it wrong in one direction and you get nothing on the bed; get it wrong in the other and you damage your build surface. That narrow window is the whole problem.<\/p>\n

The single most important number is the glass transition temperature (Tg)<\/strong> \u2014 roughly 80\u00b0C (sources put it anywhere from ~75\u00b0C to 85\u00b0C). This is where the material starts to soften and lose its solid structure. The melting point is much higher, around 260\u00b0C, while the heat-deflection temperature \u2014 the point of deformation under load \u2014 is lower, around 70\u00b0C. Chemically, PETG is PET modified with cyclohexanedimethanol (CHDM) groups, which prevents crystallisation and lowers the melting point. That’s the background; the practical takeaway is that your bed temperature wants to sit right around the Tg<\/strong>. At that point the base of the print is soft and sticky enough to bond to the platform.<\/p>\n

The second counter-intuitive trait: PETG prefers to be laid onto the bed, not squished into it.<\/strong> Almost every other material likes squish. PETG doesn’t. Raise your nozzle slightly so the first layer isn’t crushed flat, and adhesion actually improves.<\/p>\n

Bed Temperature: Hotter Isn’t Always Better<\/h2>\n

The consensus working range is 70\u201390\u00b0C<\/strong>. Sensible starting points by surface:<\/p>\n