Getting HIPS to Print Without Driving You Crazy
Unleashing The Power Of High Impact Polystyrene Filament A Strong Choice For 3D Printing
HIPS isn't as popular as PLA or PETG, but it has two uses that make it worth keeping in your printer. It's D-limonene soluble, which makes it the go-to support material for complex dual-extrusion builds. And it prints with decent impact resistance and a smooth surface that takes painting well. Most people who try it once and fail just write it off. The failure is almost always from improper drying or trying to print it like PLA. I ran a batch of prototypes on HIPS last month for a client who needed snap-fit housings. The first print failed at 50 percent because the filament was slightly damp. Warping across the bed, layer separation near the top, and the whole thing cracked during cooling. I dried it at 65 degrees Celsius for six hours in a dehydrator, dropped the first layer temperature by 5 degrees, and used a brim that was three units wide. The second attempt came out fine. Nothing dramatic. Just the normal learning curve.
What HIPS Actually Is
High Impact Polystyrene is a styrenic thermoplastic modified with polybutadiene rubber to improve toughness. That's why it's tougher than regular polystyrene, which is brittle. On a 3D printer you're looking at a glass transition temperature around 100 degrees Celsius, a recommended print temperature between 220 and 250 degrees Celsius, and a bed temperature of 90 to 110 degrees Celsius. It has moderate shrinkage, which is the main reason it warps. The rubber phase helps with impact resistance but also means the material is a bit more forgiving on layer adhesion than standard PS. The viscosity is higher than PLA, so you can't just set and forget. Your extruder needs to push through a denser melt. This matters more if you're using a direct drive extruder with a small gear ratio. Bowden setups tend to struggle a bit more with HIPS, especially at lower print speeds. Not impossible, just less consistent.
Drying Is Not Optional
HIPS absorbs moisture from the air faster than you'd expect. The rubber modifier makes it slightly hygroscopic, and wet filament prints with gurgling sounds, stringing, and weak layers. Store it in a sealed container with desiccant. If your filament has been sitting out for more than a couple of days in a humid environment, dry it before you print anything important. I use a food dehydrator set to 65 degrees Celsius for four to six hours. You can also use a filament dry box with heating elements. Some people throw it in an oven, but ovens run hot spots and can actually soften or deform the spool if the thermostat isn't accurate. Dehydrator is safer and more even. Two hours is usually enough for slightly damp filament. Six hours if it's been sitting open for a while.
Get the Full Details
Print Settings That Actually Work
Here's a baseline that works on most FDM printers. First layer temperature at 235 degrees Celsius, body temperature at 230 degrees. Bed at 100 degrees. Print speed between 40 and 60 millimeters per second for the body. Retraction settings depend on your setup, but if you have a Bowden tube, try 5 millimeters at 40 millimeters per second. Direct drive can handle 1 to 2 millimeters at similar speed. Layer height of 0.2 millimeters is a good default. The nozzle size matters too. A 0.4 millimeter nozzle is fine for most things, but if you're printing high detail supports, a 0.3 or 0.35 millimeter nozzle gives you cleaner overhangs. HIPS doesn't flow as freely as PLA, so don't push a 0.6 millimeter nozzle at high speed and expect clean results. It'll look fine structurally, but surface quality drops fast. Cooling is a weird one. HIPS actually benefits from low fan speed. 10 to 20 percent on the part cooling fan is enough. Too much cooling causes warping and poor layer adhesion because the material contracts unevenly. Let it cool slowly. If you're printing on a PEI sheet, a warm enclosure helps significantly. Even a simple cardboard box around the printer makes a noticeable difference for larger prints. The enclosed environment keeps the part temperature stable and reduces thermal gradient stress.
Bed Adhesion Strategy
HIPS sticks well to several surfaces, but the wrong choice leads to warping or parts peeling off mid-print. Glass with glue stick is the most common approach and it works if you clean the glass thoroughly between prints. The glue creates a sacrificial layer that lets you pop the part off after cooling. PEI sheets are better if you have them. HIPS bonds firmly to PEI while it's hot and releases cleanly once cooled. Paint stick is another option, though it adds extra cleanup time. I had a problem once where a 120-millimeter tall wall bracket kept delaminating from the bed despite being perfectly level. The build plate was glass, the ambient temperature was low, and the room had a draft from an HVAC vent nearby. I switched to a PEI sheet, added a 5-millimeter brim, and moved the printer away from the vent. Problem solved. Drafts are a silent killer for materials that warp easily.
Support Removal With D-Limonene
This is the main reason people choose HIPS. D-limonene dissolves it without touching most other common printing materials. You can print a model in PLA or ABS with HIPS supports, then submerge the supports in d-limonene for two to six hours depending on complexity. The supports dissolve away cleanly, leaving the main structure intact. The liquid is the real solvent, not water. D-limonene comes in bottles from suppliers like Smooth-On or can be bought as a generic from Amazon. It's derived from citrus peels. The smell is strong but not unbearable. Work in a ventilated area. Gloves are necessary because the solvent breaks down skin oils quickly and can cause irritation with prolonged contact. Safety glasses too, because splashes happen. One practical detail most guides skip: remove the part from the solvent when the supports are about 80 percent dissolved, then let capillary action finish the rest. Agitating the part in the liquid too early can damage fragile details on the main model. Check every 30 minutes for complex geometries. The dissolution rate depends on temperature. Warmer solvent works faster. A warm water bath around the container can speed things up without risking damage to the printed material.
Known Weaknesses
HIPS is not a perfect material. It has some real drawbacks that you should know before committing to it. UV exposure degrades it over time. If you're printing outdoor parts, this matters. The material becomes brittle after prolonged sunlight exposure. Indoor prototypes and functional parts are fine. Moisture absorption continues even after drying if the filament isn't stored properly. A spilled hour of open spool time can undo six hours of drying. Warping is the biggest practical issue. Large flat prints are risky without an enclosure and a brim. Thin walls can crack during cooling if the temperature drops too fast. D-limonene is expensive compared to water or alcohol-based cleaners. If you're printing supports frequently, the solvent cost adds up. It also has a shelf life. Once opened, d-limonene degrades over months. Keep the container sealed when not in use. Print speed is slower than PLA. Expect 30 to 50 percent longer print times for the same geometry. If time is critical and you don't need support dissolution, PLA or PETG might serve you better. HIPS earns its place when the support removal process saves you more time than the extra print duration costs.
Post-Processing Options
If you're painting HIPS parts, acetone vapor smoothing works selectively. The acetone softens the surface without fully melting it, creating a glossy finish. Apply the vapor for short bursts. Ten to fifteen seconds at a time. Overdo it and the part deforms. Acetone also dissolves layer lines for a smoother surface before painting. Sanding works too, but HIPS dust is fine and gets everywhere. Use a respirator if you're sanding extensively. The dust is not healthy to inhale. Acrylic cements and plastic solders bond HIPS well. If you need to join two printed pieces, this is straightforward. Ethyl acetate-based adhesives work faster than acetone for gluing. Test on a scrap piece first.
When to Choose Something Else
If you only need supports and your printer doesn't have dual extrusion, HIPS still works as a soluble support material in a single extruder setup if you design the supports to be breakaway. The dissolution advantage only applies to dual extrusion. PETG is easier to print, cheaper, and stronger in many applications. PLA is faster and simpler for non-functional prototypes. ASA has better UV resistance than HIPS and similar print characteristics. If you need outdoor durability, ASA is the better choice. For high-temperature applications, neither HIPS nor PLA is suitable. Both soften well below the temperatures that ABS or PC handles. Check your use case before committing to any material. HIPS is a specialized tool, not a general-purpose replacement for the standard filaments.
Supply Chain Notes
HIPS filament is available from most major suppliers. eSun, PolyMaker, and Hatchbox all carry it. Quality varies between batches and manufacturers. Some brands add plasticizers that change the flow characteristics, which can throw off your retraction and temperature settings. If you find a batch that prints well, stick with it. Switching brands mid-project on the same model can cause inconsistent results if the flow rates differ enough. Keep a log of the successful settings for each spool you use. Pricing is higher than PLA and PETG per kilogram, usually in the $25 to $45 range depending on quantity and brand. Factor the solvent cost into your total if you plan to use it regularly for support dissolution. A liter of d-limonene costs roughly $30 and lasts for many prints before needing replacement, but it's not free.
