PETG and ABS both get recommended as the step up from PLA once a project needs more heat resistance or durability, and that shared reputation makes them easy to lump together. They are not interchangeable. The real differences are in how easy each one is to print and what you can do to the part afterward, not in one material simply beating the other across the board.
Two different paths up from PLA
Both materials showed up in the same beginner advice for the same reason: PLA parts that soften in the sun or crack under load push people toward something sturdier. PETG got there by being marketed as “PLA plus,” easier to print than ABS while still holding up to more heat and stress. ABS got there first, as the engineering plastic most consumer printers were originally tuned around before PLA took over as the default beginner material. Neither claim is wrong, but the two solve different problems.
PETG is the easier one to live with day to day
PETG sticks to a bed aggressively, often too aggressively without a release agent, and it warps far less than ABS because it shrinks less as it cools. It can print without a heated chamber and produces noticeably less odor than ABS while running. ABS needs a hotter bed, generally 95 to 110 degC against PETG’s 70 to 85 degC, and benefits enough from an enclosure that most of its warping problems trace back to not having one. If your printer is open-frame and you are not planning to build an enclosure, PETG is the more realistic option of the two.
ABS still wins on raw heat resistance
This is the one place ABS clearly outperforms PETG. PETG holds its shape to roughly 70 to 80 degC, while ABS holds up closer to 90 to 100 degC based on manufacturer data sheets. For a phone mount that sits in a parked car or a bracket near a heat source, that gap can be the deciding factor regardless of which material is easier to print.
Layer adhesion and impact resistance favor PETG
PETG is widely reported to have better impact resistance than ABS, both in raw material testing and in how printed parts actually hold up, and it also tends to bond between layers more consistently. ABS earned its reputation as the tough, durable material mostly in comparison to PLA, not to PETG; against PETG specifically, most manufacturer and comparison data points the other way. ABS is not fragile, but if impact resistance and reliable layer strength are what decide the print, PETG is the safer bet on paper and in most published testing.
Post-processing splits the two apart
Acetone vapor smoothing, the technique that gives ABS prints a glossy surface with the layer lines melted away, works because acetone actually dissolves ABS. It does nothing useful to PETG, which resists most common solvents. PETG parts can still be sanded and painted with standard acrylics, but if a smooth, injection-molded look achieved through vapor smoothing is part of the plan, that points toward ABS specifically.
A practical choice
Pick PETG when you want an easier print, better bed adhesion, and layer strength you can count on, and the part will not sit somewhere genuinely hot. Pick ABS when the part needs to survive real heat, when you plan to acetone-smooth the surface, or when you already have a ventilated enclosure set up and the extra warping risk is not a dealbreaker. For settings once you have picked PETG, see the PETG print settings guide, and check the filament types overview if ASA or another material might fit the project better than either of these two. If ASA specifically is the alternative you are weighing, the PETG vs ASA comparison covers that pairing directly. If the project involves ABS parts with complex overhangs, HIPS filament is worth knowing about too, since it prints on nearly the same profile as ABS and dissolves away in a limonene bath as a support material.