HIPS (high impact polystyrene) gets filed under two very different categories depending on who you ask. Some printers treat it as a standalone material, a lightweight, easy-to-sand alternative to ABS for prototypes and enclosures. Others only ever touch it as a support filament, printed alongside ABS on a dual extruder machine and later dissolved away in a bath of limonene. Both uses are legitimate, and both rely on the same underlying chemistry: HIPS shares ABS’s printing temperament almost exactly, but it dissolves in a solvent that leaves ABS untouched. That single property is why HIPS carved out a niche it still holds. This guide covers the material itself, how its settings compare to other filament types, and the two jobs it does well.
What HIPS actually is
HIPS is polystyrene blended with polybutadiene rubber, roughly 5 to 10 percent rubber content depending on the formulation. The rubber phase absorbs impact energy that would otherwise crack a pure polystyrene part, which is the entire point of the “high impact” designation. On its own, polystyrene is hard, glassy, and brittle. Adding the rubber component turns it into something closer to ABS in toughness while keeping polystyrene’s machinability and low cost. Specific gravity sits around 1.04 to 1.06 g/cm3 depending on the brand, which is close to ABS and noticeably lower than PETG or nylon. Izod impact strength runs in the range of 2 to 3 ft-lb/in notched, and flexural modulus is typically around 240,000 psi, figures that put it in the same rough performance bracket as general-purpose ABS rather than the engineering-grade end of the plastics spectrum.
HIPS vs ABS: how close are they really
Close enough that most slicers list near-identical starting profiles for both. Nozzle and bed temperatures overlap almost completely, cooling requirements are the same (minimal to none), and both shrink as they cool, which means both warp on an unheated or poorly prepped bed. The differences show up at the margins. HIPS is somewhat easier to sand and files cleaner because the rubber domes are smaller and more evenly distributed, giving a finer surface texture after abrasion. It is also marginally more dimensionally stable during cooling in some formulations, though this varies enough by brand that it is not a rule to print by. Warping is still a real risk on HIPS, not eliminated, just occasionally reported as slightly less severe than a comparable ABS spool on the same printer. If you already have ASA or ABS settings dialed in, treat HIPS as a drop-in test rather than a new material to research from scratch. The ASA print settings guide covers the same warping and enclosure logic that applies here.
Nozzle temperature and extrusion settings
Most HIPS filament prints cleanly between 220°C and 250°C, with 230°C to 240°C being the common starting point across manufacturer data sheets. Lower within that range gives crisper details and less stringing; higher improves layer bonding on parts that show delamination or cracking between layers. If a print splits along layer lines, the fix is usually a hotter nozzle or a thinner layer height before anything else, the same troubleshooting order used for ABS. Retraction settings transfer fairly directly from an ABS profile since both materials string in similar ways, though HIPS from some brands runs slightly stringier at the top of its temperature window.
Bed temperature and enclosure needs
A heated bed running 90°C to 110°C is standard, with some formulations printing acceptably as low as 75°C to 95°C. Below that range, corners lift and the first layer struggles to stay flat, particularly on parts with a large footprint. An ABS slurry (scrap ABS dissolved in acetone, brushed onto glass) works as an adhesion aid for HIPS just as it does for ABS, since the chemistry of the bonding surface does not care which polystyrene-family plastic is sitting on top of it. For anything beyond small to medium parts, an enclosure is worth having. It is not strictly mandatory the way it is for polycarbonate, but draft-free, stable ambient heat around the print reduces the temperature differential between the outer walls and the print bed, which is the actual mechanism behind warping. Printers without an enclosure can still get good results on HIPS by keeping room drafts away from the printer and using a brim on tall or wide parts.
Print speed and cooling
Typical speeds fall between 35 and 60 mm/s. Cooling fans should stay low or off entirely for the first several layers and generally throughout the print, since aggressive part cooling on HIPS reintroduces the same problem it solves on PLA: it accelerates the temperature drop that causes layer separation and warping. A minimum wall thickness of around 1.0 mm keeps parts from cracking under their own shrinkage stress, and infill density around 20 percent is a reasonable default for standalone HIPS parts that do not need full structural rigidity. Complex geometries with sharp overhangs benefit from slower speeds on the outer perimeters specifically, since that is where the largest thermal gradient exists.
HIPS as a dissolvable support for ABS
This is the use case that keeps HIPS in circulation even though breakaway and water-soluble alternatives exist for other materials. When printing ABS parts with steep overhangs, internal channels, or interlocking assemblies, HIPS printed on a second extruder gives you a support structure that comes out with a solvent bath instead of pliers, tweezers, and a lot of patience. The reason it works specifically with ABS and not, say, PLA, is that both materials tolerate the same nozzle and bed temperatures, so a dual extrusion print does not have to compromise on either material’s settings mid-print. Minimum wall thickness for HIPS used as a support structure should be a bit thicker than for standalone parts, around 1.2 mm, so the support survives the print itself without collapsing before the dissolving step ever happens. This is functionally the same design logic covered in the PETG vs ABS comparison, where material pairing decisions come down to matching thermal behavior, not just mechanical properties.
Dissolving HIPS in limonene: process and safety
D-limonene is a citrus-derived solvent, the compound responsible for the smell of orange peel, extracted and concentrated for industrial use. It dissolves polystyrene (and therefore HIPS) without meaningfully attacking cured ABS, which is the whole reason this support pairing exists. The typical process is to submerge the printed part fully in a sealed container of d-limonene and let it sit, usually 12 to 24 hours depending on how much support material needs to dissolve and how saturated the limonene bath already is from prior use. Support-heavy prints or thick support structures can take closer to two or three days at room temperature. A heated ultrasonic cleaner running the bath at 40°C to 50°C speeds this up considerably, sometimes to 2 to 4 hours, though not everyone has access to one. Agitating or shaking the container periodically helps loosen softened HIPS from the ABS surface faster than a still bath.
Safety matters here more than with water-based support removal. D-limonene has a flash point around 48°C, which classifies it as a flammable liquid, and it is a skin and eye irritant with sensitization potential on repeated exposure. It should be used in a ventilated space, kept in a sealed container away from heat sources, and handled with gloves. It is not acutely toxic by casual contact, but it is not something to leave open on a workbench either. Limonene degrades in effectiveness as it absorbs dissolved HIPS, so a bath used for several prints in a row will dissolve support material more slowly than a fresh one, and heavily pigmented HIPS (black or dark colors especially) can occasionally leach pigment into the bath and stain a light-colored ABS part during a long soak.
Post-processing: sanding and smoothing
HIPS sands easily and predictably, which is one of its main selling points as a standalone material. Starting around 220 grit and working up to finer grits removes layer lines quickly without gumming up the sandpaper the way softer filaments sometimes do. It also machines cleanly on a rotary tool or mill, which is why it shows up in machined prototype workflows outside of pure 3D printing. Because HIPS is polystyrene-based, acetone vapor smoothing works on it in much the same way it works on ABS, softening the outer surface and melting away visible layer lines. The same ventilation precautions that apply to acetone smoothing on ABS apply here. Painting and gluing both take well to a sanded HIPS surface, another reason it gets used for display models and enclosures that need a finished look.
UV resistance and outdoor use
HIPS shares ABS’s weak spot here: neither holds up well under sustained UV exposure. Outdoor parts printed in HIPS will yellow, lose surface gloss, and gradually become more brittle over months of sun exposure, the same degradation pattern seen in unprotected ABS. This is not a defect specific to HIPS, it is a property of styrene-based polymers generally. If a part needs to live outdoors long-term, ASA is the better choice precisely because it was formulated to resist this kind of UV breakdown. HIPS and ABS are both indoor-use or short-term-outdoor materials unless painted with a UV-resistant coating afterward.
Storage and moisture sensitivity
HIPS absorbs less moisture than nylon, PVA, or even PETG, and some manufacturer literature describes it as effectively non-hygroscopic under normal storage conditions. In practice this means HIPS tolerates open-air storage better than most engineering filaments, but it is not entirely immune. Spools left unsealed in humid environments for extended periods can still pick up enough moisture to cause minor surface defects, tiny bubbles or a slightly rougher finish, particularly noticeable on light colors. Drying at around 70°C to 80°C for a few hours before a demanding print is cheap insurance and standard practice among people who print HIPS regularly, even if the material forgives neglect better than most.
Typical applications
Standalone HIPS shows up in lightweight prototypes where machinability and paintability matter more than raw strength, in enclosures and housings that get sanded and painted for a finished appearance, and in jigs or fixtures that benefit from easy post-machining. As a support material, it is almost exclusively paired with ABS on dual extruder or IDEX printers for parts with complex internal geometry, articulated assemblies printed pre-joined, or overhangs too steep for bridging alone. It is less common as a support for PLA or PETG prints, since those materials pair better with water-soluble PVA at lower, more compatible printing temperatures.
HIPS printing checklist
- Set nozzle temperature between 220°C and 250°C, starting around 230°C to 240°C and adjusting for stringing or layer bonding issues
- Heat the bed to 90°C to 110°C and use an ABS slurry or similar adhesive if parts lift at the corners
- Use an enclosure or at least a draft-free area for parts larger than a few centimeters to control warping
- Keep part cooling fans low or off throughout the print
- Dry the spool at 70°C to 80°C for a few hours if it has been stored unsealed or the surface finish looks off
- For dissolvable supports, print at 1.2 mm minimum wall thickness and set up dual extrusion with matched ABS and HIPS temperature profiles
- Submerge finished parts in a sealed d-limonene bath for 12 to 24 hours, longer for dense supports, and agitate periodically
- Handle d-limonene in a ventilated area with gloves, away from open flame, since its flash point is around 48°C