High Impact Polystyrene filament occupies a niche role in desktop FDM that few makers explore: it is the ideal soluble support material for ABS printing, dissolving cleanly in d-limonene solvent while leaving the ABS model completely intact. The MatterHackers HIPS guide identifies the key advantage over PVA — the competing water-soluble support material — as temperature compatibility: HIPS prints at 220–240°C, the same range as ABS, making dual-extrusion support printing with HIPS and ABS mechanically stable and dimensionally accurate. PVA degrades above 210°C and produces moisture-driven print failures when paired with high-temperature materials. Understanding HIPS's properties, the limonene dissolution process, and the dual-extrusion workflow reveals why it is the professional choice for complex ABS parts that would be impossible or impractical to deprime manually.

Material Properties of HIPS

HIPS is polystyrene modified with polybutadiene rubber to improve impact resistance — the same material used in disposable cutlery, packaging, and consumer electronics enclosures. As a standalone print material it is reasonably tough, lightweight, and accepts paint well after surface preparation. Its density is lower than ABS, which makes HIPS models notably lighter than equivalent ABS prints of the same geometry. Printed standalone HIPS has acceptable surface quality but limited engineering application: its chemical resistance is lower than ABS, and its heat resistance falls below ABS's glass transition of 100°C. As a support material, however, HIPS properties align almost perfectly with ABS model material: matching print temperature, similar thermal expansion coefficient reducing delamination at the interface, and dimensional stability during the print that prevents the support from warping away from the model mid-job. The dissolution chemistry is highly selective — d-limonene attacks polystyrene aggressively while having no measurable effect on ABS, which is chemically distinct despite printing at similar temperatures.

Limonene Dissolution: Process and Safety

D-limonene is a citrus-derived solvent that occurs naturally in orange peel oil. It is far less hazardous than acetone, which is used to smooth ABS surfaces — limonene has a relatively low toxicity profile and a pleasant citrus odor, though it should still be used in a well-ventilated area and kept away from skin for extended contact. Dissolution works by submerging the completed ABS-HIPS part in a container of d-limonene and waiting. Thin HIPS support structures typically dissolve within one to four hours at room temperature; denser support geometry may require overnight soaking or mild agitation. Warm limonene accelerates dissolution but should not be heated above 50°C, at which point vapors become significant. After removal, rinse the ABS part in isopropyl alcohol to remove limonene residue and allow to dry fully before handling the finished surface. D-limonene can be reused until it becomes saturated with dissolved polystyrene — a single container typically handles dozens of print jobs before replacement is needed.

HIPS vs PVA: Choosing the Right Soluble Support

PVA (polyvinyl alcohol) is the dominant water-soluble support material for PLA dual-extrusion printing, and for PLA it is excellent — dissolves in plain water, prints at PLA-compatible temperatures, and produces clean interface separations. The problem begins when paired with high-temperature materials. PETG at 230–250°C degrades PVA at the interface. ABS at 230–240°C does the same, producing stringy, difficult-to-remove support that defeats the purpose of solubility. HIPS was specifically developed to address this gap: matching ABS temperatures exactly, dissolving in a different solvent, and producing clean breakaway at the ABS-HIPS interface. For ABS prints with internal channels, deeply recessed features, or complex overhangs that require dense support, HIPS is not just the better choice — it is often the only practical one. The solvent cost of d-limonene is higher than water, but a container lasts for months of regular use.

Dual Extrusion Setup and Slicer Configuration

Dual extrusion with HIPS support requires a printer with two independent hotends capable of maintaining ABS temperatures simultaneously — machines like the Raise3D Pro series, the BCN3D Sigma, or modified Prusa MMU setups. The slicer must be configured with ABS as the model material and HIPS as the dedicated support material, with the support interface layer set to HIPS. Critically, set the support interface distance to 0.1–0.2mm rather than zero: a small air gap at the ABS-HIPS boundary makes dissolution faster and prevents micro-bonding between the two materials that can leave a rough surface on the model. Prime towers are essential with HIPS dual extrusion — both materials require proper priming after each tool change to prevent color contamination and ensure consistent flow. Allow adequate ooze shield distance if your machine generates significant ooze from the inactive nozzle during long travel moves between model and support regions.

Practical Use Cases and Limitations

HIPS support is most valuable for ABS parts with internal cavities that cannot be reached for manual support removal — hydraulic manifolds, pipe fittings, hollow structural components, and complex functional assemblies where support scars on interior surfaces would impair function. It is equally valuable for external overhangs on cosmetic surfaces where manual support removal always leaves visible marks regardless of interface settings. The limitations are real: HIPS requires a dual-extrusion printer, an ABS-compatible enclosure, and the ongoing cost of d-limonene. For simple geometries where supports are accessible and surface quality on the support face is not critical, standard interface materials and manual removal remain faster and cheaper. HIPS also cannot be used with PETG due to temperature incompatibility at the interface — PVA remains the correct soluble support pairing for PETG, despite its moisture sensitivity challenges.

What It Means for Makers

HIPS unlocks a category of ABS prints that were previously impractical without industrial equipment — complex enclosed geometries, clean cosmetic surfaces on all faces, and production-quality parts without hours of support removal. If you already own an ABS-capable dual-extrusion printer, adding HIPS to your workflow costs little: a kilogram of HIPS filament is inexpensive, a bottle of d-limonene handles months of use, and the slicer setup is straightforward. The payoff is parts that look and function as designed across every surface, not just the ones you could reach with pliers.

Sources