What Causes a 3D Printer to Print Rough Surfaces? (How to Fix?)

For the majority of the 3D printing projects, how the model looks is a significant aspect of determining whether the print was a success or not, considering that most enthusiasts use their 3D printers for printing models with aesthetical purposes.

On the other hand, getting a model to look perfect is also one of the more challenging things in 3D printing – since the possibility of something going wrong and causing an imperfection on the surface is pretty high with a slight misconfiguration or mechanical error.

Today, we will be addressing the common issue of a 3D printer printing rough surfaces instead of smooth ones, making the 3D printed model look and feel underwhelming and low-quality, which is a dealbreaker for most 3D printing projects.

So, what causes a 3D printer to print rough surfaces?

A few distinct factors can cause your 3D printer to print rough surfaces, which we have listed below:

  • Over-extrusion
  • Misconfigured Z offset value
  • Extruder assembly problems (loose belts, worn-out gears, etc.)
  • Filament problems (moisture, lousy quality, etc.)

As you may have noticed, the common point between all these factors is that they create inconsistencies in the extrusion of the plastic, which present themselves in the form of rough surfaces.

Moving forward, we will go into the reasons that can cause a 3D printer to print rough surfaces in better detail, find out what we can do to fix this problem, and take a quick look at the signs that can help us identify the existence of rough surfaces on a model.

What Causes a 3D Printer to Print Rough Surfaces?

In this section, we will take a deeper look into each factor that can cause the problem of your 3D printer printing rough surfaces. This process will allow us to understand how each culprit can cause the issue and help us identify the one giving us trouble. 


Over-extrusion, which means that the 3D printing is extruding more plastic than intended, is the first thing that comes to mind in the case of the appearance of rough surfaces on the print.

When more plastic than calculated comes out of the nozzle during parts of the printing process, the overflowing plastic causes inconsistencies on the print’s surface in the shape of bumps and patches, causing the issue of rough surfaces.

As over-extrusion is an issue that will create many other unpleasant symptoms, such as oozing, layer shifting, and an overall loss of surface quality, it’s often reasonably straightforward to find out if over-extrusion is indeed the issue in your case.

Misconfigured Z Offset Value

Incorrectly configuring the Z offset value, which determines the amount of space between the nozzle and the build surface at the start of the print, is another factor that can contribute to your 3D printer printing rough surfaces.

While a misconfigured Z offset value will primarily cause issues on the first layer of the print, it’s possible to observe these faults carrying over to the top of the print depending on the severity.

The inconsistencies that appear on the first layer can cause each following layer to also become inconsistent due to these inconsistencies being unaccounted for, causing your print to have a rough surface.

Getting the Z offset correct is vital for the overall health of the 3D printing process due to its heavy impact on the printing of the first layer. On the other hand, as Z offset configuration can sometimes be challenging, we highly recommend using an auto bed leveling sensor, such as BLTouch, to avoid such issues altogether.

Extruder Assembly Problems

The extruder assembly consists of many parts, and considering that each of these parts plays a vital role in the correct extrusion of the plastic, it’s highly likely for problems to occur in the extruder assembly, especially after the first setup or high amounts of usage.

Below, we have listed the potential extruder-related causes that can cause your 3D printer to print rough surfaces:

  • Clogged nozzle 
  • Loose extruder gears
  • Loose extruder belts
  • Skipping extruder motor
  • Z-axis binding

Whether you face issues related to the extruder or not, it’s often a good idea to maintain the extruder assembly now and then to prolong the lifespan of the components and avoid extruder problems down the road.

Filament Problems

Even if no issues are troubling your 3D printer, the filament itself can easily cause the extrusion to become inconsistent and create the problem of your 3D printer printing rough surfaces.

Below, we have listed the potential filament-related problems that can cause your 3D printer to print rough surfaces:

  • Low-quality filament – Low-quality filament refers to the material composition of the filament being suboptimal, which can cause your 3D printer to struggle to extrude it consistently and evenly.
  • Inconsistent filament – Inconsistent filament refers to the diameter of the filament showing variance throughout the spool, which throws the 3D printer’s calculations off and causes it to extrude more or less filament than intended.
  • Moisture in filament – As the moisture in the filament gets released once the filament comes into contact with the nozzle, inconsistencies appear on the print due to the unexpected increase of pressure in the hot end.
  • Degraded (expired) filament – Filament stored improperly for prolonged amounts of time eventually degrades, making it unsuitable for usage.

Keeping a few different brands of filament handy is usually a great idea to rule out the possibility of the filament being the problem before diving deeper into the configuration and the hardware of your 3D printer.

How to Fix 3D Printer Printing Rough Surfaces?

As a few distinct culprits can be behind the issue of your 3D printer printing rough surfaces, fixing the problem can be a lengthy process that requires you to try a few different solutions until you find the one that works.

Below are the fixes we recommend applying to solve the problem of your 3D printer printing rough surfaces, which covers the majority of culprits that can cause this issue to appear:

  • Re-configure the parameters that can contribute to over-extrusion. Extrusion multiplier, print temperature, and filament diameter are the primary parameters to look out for here, as any of these parameters can individually cause over-extrusion. 
  • Re-calculate and re-configure the Z offset value. The Z offset parameter should be set to a value where the space between the nozzle and the print bed should match the thickness of a paper after homing.
  • Maintain the extruder assembly. Frequently tightening the gears and the belts of the extruder, cleaning and lubricating the Z rod, cleaning the nozzle, observing the stepper motor for any issues, and maintaining all the other extruder components will ensure that the extruder assembly is not the source of the problem.
  • Buy a fresh spool of high-quality filament. The best way to rule out the possibility of the filament causing your problem is to buy a fresh, high-quality spool of filament from a trusted brand, even if it’s slightly more expensive.

More often than not, following the steps above should fix the problem and allow your 3D printer to print smooth layers once again.

How to Identify Rough Surfaces on a 3D Printed Model?

Being familiar with what to look out for in a scenario where you suspect that your 3D printer may be printing rough surfaces is a big step towards solving the problem; since applying the appropriate solution requires being familiar with the issue.

The primary sign that a 3D printed model suffers from the issue of rough surfaces is the appearance of patterns such as waves, bumps, and patches throughout the surface, commonly in an inconsistent manner that makes such patterns glaringly apparent compared to the correctly printed areas.

Due to these patterns essentially being a product of inconsistency in the way the plastic is extruded, they won’t look or feel right, making it a pretty straightforward task to identify them without too much effort.

Wrapping Up

Even though solving the issue of your 3D printer printing rough surfaces can be a process due to the number of factors involved, you should be able to get it back in optimal working condition without needing to send it in for repair.

To quickly recap, it wouldn’t be wrong to say that any factor that can cause inconsistencies in how the 3D printer extrudes the filament can cause rough surfaces, as the extrusion of the plastic needs to be seamless for smooth surfaces.

Factors such as over-extrusion, Z offset misconfiguration, filament-related problems, and issues that can cause the extruder assembly to operate suboptimally are usually the first things that come to mind in this case, but it’s a good idea to keep a lookout for anything that can cause inconsistencies.

Happy printing!