What Is Infill in 3D Printing

What Is Infill in 3D Printing
Why It Matters
When it comes to 3D printing, infill plays a critical role in determining the strength, weight, cost, and print time of your object. Whether you’re printing a functional prototype or a decorative model, understanding infill can help you make smarter design and material choices. At BritForge 3D, we optimise every print to meet your needs and infill is a key part of that process.
What Is Infill?
Infill refers to the internal structure of a 3D printed object. Instead of printing a solid block, most parts are printed with an internal pattern that gives them strength while saving material. The outer shell (or perimeter) is printed solid, while the inside is partially hollow filled with a repeating pattern called infill.
Why Infill Matters
- Strength: More infill = stronger part
- Weight: Less infill = lighter part
- Print Time: Higher infill increases time and cost
- Purpose: Match infill to function (display vs. functional)
Common Infill Patterns
- Grid: Balanced strength and speed. Good for most parts.
- Gyroid: Excellent strength in all directions and efficient material use.
- Honeycomb: Lightweight with moderate strength. Popular for visual appeal.
- Lines: Fastest to print, used for basic prototypes.
Recommended Infill Percentages
| Use Case | Infill Percentage | Notes |
|---|---|---|
| Display Model | 10–15% | Light and fast to print |
| Functional Part | 25–50% | Stronger, better durability |
| Structural Load-Bearing | 50–100% | Max strength, longer print time |
How Infill Affects Cost
Higher infill means more material and longer print times which increases the cost. For example, changing from 15% to 50% infill might double the amount of filament used. At BritForge 3D, we help you choose the best balance of strength and budget for your application.
Infill Tips
- Use low infill for decorative or non-functional models
- Choose gyroid or grid for strength and reliability
- Keep in mind that more infill doesn’t always equal better results
- Use multiple perimeters instead of just increasing infill
How BritForge 3D Optimises Infill
We analyse every print job to recommend an ideal infill percentage and pattern based on use, strength, and cost. Whether you’re printing a bracket, toy, or prototype, we tailor each print to perform as needed saving you time and money.
Conclusion
Infill is more than just a setting it’s the backbone of your 3D printed part. Understanding how it works helps you make better decisions, whether you’re designing a prototype or ordering your first custom part. Let BritForge 3D help you find the perfect infill for your next project.

Top 5 Free Websites to Find 3D Printable Models
One of the best things about 3D printing is the incredible number of free models you can download and print no design experience needed! Whether you’re looking for practical tools, fun gadgets, miniatures, or educational models, these five websites are go-to sources. At BritForge 3D, we work with all of them and can help you bring any downloaded model to life with professional-quality results.
1. Printables by Prusa
Printables.com is a rapidly growing model-sharing platform from Prusa Research. It’s 100% free and features high-quality STL files from trusted creators. You can browse by category or popularity, and most listings come with print settings and tips.
- ✅ Great for functional prints and hobby projects
- ✅ Active community with frequent competitions
- ✅ No account needed to download
2. Thingiverse
Thingiverse is the original 3D model hub with thousands of files. It’s great for finding creative or educational prints, although quality varies since anyone can upload files.
- ✅ Massive variety of models
- ✅ Ideal for schools and hobbyists
- ⚠️ Check printability before ordering
3. MyMiniFactory
MyMiniFactory is known for professionally curated models and supports many independent designers. It’s especially good for gaming figures, props, and premium-quality designs. Many are free, but some are paid.
- ✅ Excellent for miniatures and cosplay items
- ✅ Filters by licence and printer type
- ✅ Print-ready files with instructions
4. Cults3D
Cults3D is a French-based platform with a creative and artistic twist. You’ll find unique home decor, jewellery, and design-focused models. Some files are free, and others require a small fee.
- ✅ Great for creative and niche projects
- ✅ Many free and high-resolution files
- ⚠️ Mixed file licensing, check before commercial use
5. NASA 3D Resources
NASA 3D Resources offers a curated collection of space-related models, including spacecraft, rovers, and planets all in the public domain. It’s a fantastic tool for educators and STEM outreach.
- ✅ Educational and scientifically accurate
- ✅ Free and public domain
- ✅ Perfect for schools and museums
Tips for Downloading Printable Models
- Always check the file type (.STL, .OBJ, etc.)
- Look for “print-ready” or “tested” labels
- Check model scale and orientation
- Use slicing software like Cura to preview before printing
Print Your Files with BritForge 3D
Once you’ve downloaded your model, simply upload it to BritForge 3D. We’ll review it, suggest the best material, and provide instant pricing. Whether you’re printing a rocket, a phone stand, or a full chess set, we’ll deliver precise, high-quality results all made in the UK.
Conclusion
With thousands of free 3D models available online, the only limit is your imagination. Explore, download, and start printing and let BritForge 3D handle the hard part for you. No printer? No problem.

Understanding Print Orientation and Part Strength
Print orientation is one of the most important yet often overlooked aspects of successful 3D printing. How a part is positioned on the print bed affects not only how it looks but also how strong it is in real-world use. At BritForge 3D, we evaluate each model to ensure it’s oriented for the best balance of strength, accuracy, and surface finish.
What Is Print Orientation?
Print orientation refers to how your 3D model is positioned during the printing process. This determines how layers are built up, how supports are generated, and how forces act on the finished part.
Why Print Orientation Matters
- Part Strength: FDM prints are weakest between layers. Orient your part to resist stress across layers.
- Surface Finish: Vertical surfaces print smoother than horizontal overhangs.
- Print Time & Supports: Orientation affects how much support material is required and how long a print takes.
- Accuracy: Flat surfaces on the print bed come out cleaner and more dimensionally accurate.
Layer Adhesion and Strength
In FDM 3D printing, parts are built layer by layer. The bond between layers isn’t as strong as the material itself, which means parts can be prone to delamination under stress especially if printed in the wrong orientation. For maximum strength, orient parts so the load is parallel to the layers.
Examples of Optimal Orientation
- Brackets: Print with the flat face on the bed and the arms upright to handle load across the layer lines.
- Hinges or Clips: Align so stress points run along, not between, layers.
- Decorative Models: Choose orientation for better detail visibility and smooth surfaces.
Support Material Considerations
Changing orientation can dramatically reduce the need for supports saving time and material. Parts printed with minimal overhangs are easier to post-process and have a better finish.
Tips for Better Print Orientation
- Minimise large overhangs (greater than 45°)
- Orient parts with the flattest side down for bed adhesion
- Consider the functional load design for it!
- Use preview features in slicing software to evaluate orientation
How BritForge 3D Helps
When you upload a file to BritForge 3D, we assess print orientation to ensure it meets your needs. Whether you’re making a working part or a display model, we tweak orientation, supports, and slicing settings to optimise every job.
Conclusion
Understanding how orientation affects 3D printed part strength can be the difference between success and failure. Our team at BritForge 3D takes the guesswork out delivering durable, high-quality prints designed for real-world performance.

How Long Does 3D Printing Take?
A Practical Guide
One of the most common questions we get at BritForge 3D is: “How long will my 3D print take?”
The answer depends on several factors, from the size and complexity of the model to the chosen material and print resolution. In this guide, we’ll break it down so you know what to expect whether you’re printing a simple keychain or a fully functional prototype.
What Affects 3D Print Time?
- Model Size: Larger models take longer due to more layers and longer tool paths.
- Print Layer Height: Thinner layers = better quality but slower prints.
- Infill Percentage: More internal material means longer print times.
- Number of Parts: Printing multiple objects increases time, especially if done all at once.
- Printer Type: FDM printers are generally slower than resin (SLA/DLP) printers for small, detailed parts.
Typical Print Times
| Item Type | Estimated Time | Notes |
|---|---|---|
| Keychain or Small Figurine | 30 mins – 2 hours | Low infill, basic shape |
| Phone Stand or Medium Bracket | 2 – 6 hours | Functional item with moderate infill |
| Large Prototype or Cosplay Part | 8 – 24+ hours | Higher resolution and material use |
FDM vs. Resin Print Speeds
FDM Printing: Generally slower but more economical for larger prints.
Resin Printing: Faster for small detailed items, but requires more post-processing (washing and curing).
Other Time Factors
- Pre-Print Setup: File prep, orientation, slicing and machine calibration.
- Post-Processing: Removing supports, sanding, curing (for resin).
- Queue Time: If demand is high, your print may be scheduled in a queue especially for bulk or business orders.
Speed vs. Quality
If you choose faster printing (thicker layers), you may sacrifice surface detail and finish. For display models, thinner layers look better. For functional items, speed and strength may be more important. At BritForge 3D, we help you balance quality and turnaround time to match your needs and budget.
How BritForge 3D Delivers Efficient Prints
We use high-speed, industrial-grade printers and fine-tuned slicing profiles to reduce print times without compromising quality. You’ll get a time estimate when you upload your file, and we’ll keep you informed every step of the way.
Conclusion
3D printing times vary, but with the right setup and planning, your prints can be completed faster than you might expect. Whether you need something in 24 hours or just want to understand the process, BritForge 3D is here to deliver precision prints on time, every time.

PLA vs PETG vs ABS:
Which 3D Printing Filament Should You Choose?
Choosing the right filament is one of the most important decisions you’ll make when starting a 3D printing project. At BritForge3D, we work with a wide range of materials daily — but three of the most popular are PLA, PETG, and ABS. Each has unique characteristics that make it ideal for different applications. This guide will help you decide which is right for you.
1. PLA (Polylactic Acid)
Overview: PLA is the most beginner-friendly filament. It’s derived from renewable sources like corn starch and is biodegradable under the right conditions.
Pros:
- Easy to print with – low warping
- Low printing temperature (180–220°C)
- Minimal odour during printing
- Great for detailed, cosmetic prints
Cons:
- Brittle – not ideal for functional parts
- Low heat resistance – softens at 60°C
Best for: Prototypes, toys, models, beginner projects
2. PETG (Polyethylene Terephthalate Glycol)
Overview: PETG strikes a balance between ease of printing and strength. It’s strong, slightly flexible, and more durable than PLA.
Pros:
- High strength and good impact resistance
- Better temperature resistance than PLA
- Water-resistant and food-safe (when printed cleanly)
- Good layer adhesion, minimal shrinkage
Cons:
- Prone to stringing
- Can absorb moisture quickly
Best for: Functional parts, mechanical components, containers, outdoor items
3. ABS (Acrylonitrile Butadiene Styrene)
Overview: ABS is a strong industrial plastic known for its durability. It’s widely used in the automotive and engineering industries but can be trickier to print.
Pros:
- High impact strength
- Better temperature resistance (up to 100°C)
- Can be smoothed with acetone vapour for glossy finish
Cons:
- Requires a heated bed and enclosure to avoid warping
- Strong odour – needs ventilation
Best for: Functional parts, automotive parts, enclosures, mechanical assemblies
4. Environmental Considerations
If sustainability is a concern, PLA is biodegradable and more environmentally friendly. PETG is recyclable, while ABS is made from petroleum and poses the biggest environmental impact. However, ABS’s durability often means fewer reprints.
5. Printing Requirements
| Filament | Print Temp | Bed Temp | Ease of Use | Strength |
|---|---|---|---|---|
| PLA | 180–220°C | 20–60°C | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ |
| PETG | 220–250°C | 70–90°C | ⭐⭐⭐ | ⭐⭐⭐⭐ |
| ABS | 230–260°C | 90–110°C | ⭐⭐ | ⭐⭐⭐⭐⭐ |
6. Which Filament is Right for You?
It depends on your goals:
- PLA if you’re just starting or need high-detail models
- PETG for strong, flexible, and water-resistant parts
- ABS if you need heat resistance and industrial-level durability
For most hobbyists and small UK businesses, PLA and PETG cover 90% of use cases. ABS is great, but needs more control and safety considerations.
7. Let BritForge3D Help You Choose
If you’re unsure which filament suits your project best, feel free to contact us. We’ll help guide you based on strength, flexibility, budget, or even weather-resistance. You can even upload your 3D file and we’ll recommend the best material to get you the best results.
Conclusion
Understanding the differences between PLA, PETG, and ABS is key to getting great results in your 3D prints. Each filament has its strengths, and the best choice depends on your application. No matter your material, BritForge3D is here to help bring your ideas to life — reliably, affordably, and right here in the UK.

A Technical Guide – Part Four
Material Selection for Functional 3D Printed Parts
One of the most common reasons a 3D printed part fails is not poor print quality, bad settings, or even weak design. It is simply the wrong material being used for the job. Material choice sits at the heart of functional 3D printing, and yet it is often treated as an afterthought. To design parts that work reliably, material selection must be intentional and informed.
When people are new to 3D printing, they often choose materials based on convenience. They pick whatever prints easily, looks good, or happens to be loaded in the printer. While this approach may work for visual models or short-term prototypes, it quickly breaks down when parts are expected to carry load, withstand heat, or survive long-term use.
To understand why material choice matters so much, we need to remember what 3D printed parts are made of. Unlike metals or machined plastics, most desktop 3D prints are built from thermoplastics. These materials soften when heated and harden when cooled, and their behaviour is strongly influenced by temperature, stress, and time.
Each thermoplastic has a unique combination of stiffness, toughness, flexibility, and heat resistance. No single material excels at everything. Choosing the right one is about matching those properties to the way the part will be used, not about finding a “best” filament overall.
PLA is a good place to start because it is so widely used. PLA prints easily, holds fine detail, and produces dimensionally accurate parts. It is stiff, which means it resists bending under light loads. These characteristics make PLA excellent for visual models, alignment tools, and prototypes where appearance and accuracy matter more than durability.
However, PLA has significant limitations. It is brittle, meaning it tends to crack rather than deform when overloaded. It also has poor heat resistance. Even moderate warmth can cause PLA to soften, leading to warping or permanent deformation. Over time, PLA also suffers from creep, slowly changing shape under constant load. For functional parts expected to last, these weaknesses are critical.
PETG is often chosen as the next step up, and for good reason. PETG is tougher than PLA and far more forgiving under stress. Instead of cracking, it tends to flex slightly and recover. This makes PETG suitable for clips, enclosures, brackets, and parts that experience occasional impact or vibration.
PETG also handles moisture well and does not become brittle with age. However, its flexibility can be a disadvantage in applications where rigidity is essential. PETG parts may slowly deform under sustained load if not designed carefully, especially in warm environments. This means geometry and wall thickness become particularly important when using PETG.
ABS represents a shift toward true engineering plastics. ABS is tougher, more impact-resistant, and far more heat tolerant than PLA or PETG. It has been used in manufactured products for decades, which is why it appears in automotive interiors and consumer electronics housings.
The challenge with ABS is not performance, but process control. ABS shrinks significantly as it cools, which can lead to warping and cracking if the printing environment is not controlled. Enclosures, stable temperatures, and careful cooling are essential. When printed correctly, ABS produces parts suitable for demanding functional roles.
ASA is closely related to ABS but adds an important advantage: resistance to ultraviolet light. Where ABS can degrade and become brittle outdoors, ASA maintains its properties under sunlight. This makes ASA an excellent choice for external components, outdoor enclosures, and parts exposed to weather.
Like ABS, ASA requires controlled printing conditions. The payoff is long-term durability in environments that would quickly destroy less robust materials. For outdoor functional parts, ASA is often the correct choice even if it is more challenging to print.
Nylon takes functional performance even further. Nylon is exceptionally tough, fatigue-resistant, and capable of absorbing repeated stress without cracking. Where PLA snaps and PETG bends, nylon often flexes and returns to shape. This makes it ideal for hinges, gears, clips, and mechanical components.
However, nylon introduces a new challenge: moisture sensitivity. Nylon absorbs water from the air, and this dramatically affects both printing behaviour and final part strength. Printing nylon successfully requires dry storage, controlled environments, and careful preparation. When handled correctly, nylon produces some of the strongest plastic parts available on desktop machines.
Composite materials, such as carbon fibre–filled filaments, are often misunderstood. These materials add stiffness and dimensional stability but usually reduce layer adhesion and impact resistance. They are excellent for rigid parts that must not flex, but poor choices for components that experience shock or repeated loading.
It is also important to understand that material behaviour is closely linked to print orientation. A material that performs well along the layer lines may perform poorly across them. Material choice and orientation must be considered together, not in isolation.
Environmental conditions further complicate material selection. Exposure to heat, sunlight, chemicals, and moisture all influence how plastics age. A part that performs perfectly indoors may fail quickly outdoors if the material is not suited to that environment.
Time is another factor. Some materials maintain their properties for years, while others slowly degrade. Creep, embrittlement, and UV damage are long-term processes that must be considered for permanent installations.
Professional designers approach material selection by asking how the part will live its life. Will it be loaded constantly or occasionally? Will it experience heat? Will it be indoors or outdoors? Will it be assembled once or many times? These questions guide material choice far more effectively than print convenience.
At BritForge3D, material selection is never an afterthought. Each project begins by understanding the application and choosing a material that supports it. This approach prevents failure, reduces reprints, and ensures parts perform as intended.
Material choice is not about finding the strongest filament. It is about finding the right filament. When material properties align with design intent, 3D printed parts stop being fragile prototypes and become reliable functional components.
Closing Thoughts
Understanding materials is a turning point in learning 3D printing. Once you stop asking “what prints easiest?” and start asking “what will this part experience?”, your results improve dramatically. Material selection transforms 3D printing from a hobby into a manufacturing tool.
In the next technical guide, we will explore print speed, acceleration, and motion control, and how these hidden settings influence strength, accuracy, and reliability.
Guide 4 Summary – Material Selection for Functional Parts
This guide focused on the critical role material choice plays in determining whether a part succeeds or fails. By examining how different plastics respond to heat, load, moisture, and time, you learned why selecting material based on real-world use is essential.
The key lesson is that there is no “best” filament — only the right material for a specific application. Understanding material behaviour allows you to design parts that last rather than merely print successfully.
In the next guide, we explore how print speed, acceleration, and motion control quietly influence strength, accuracy, and consistency.

A Technical Guide – Part Five
Print Speed, Acceleration, and Motion Control in 3D Printing
When people talk about print speed, they often think in simple terms: faster means lower quality, slower means higher quality. While there is some truth to this, it hides a much more important reality. Speed in 3D printing is not a single setting — it is a complex interaction between motion, temperature, material behaviour, and time.
To understand why speed matters, we need to think about what the printer is actually doing. At every moment, molten plastic is being pushed through a nozzle and placed precisely onto a previous layer. That plastic must still be hot enough to bond properly, but cool enough to hold its shape. Speed directly affects this balance.
When printing too fast, plastic is stretched as it leaves the nozzle. This stretching reduces the contact area between layers, weakening the bond. The part may look acceptable on the outside but fail internally when stressed. This is why some fast prints snap along layer lines even though they appear solid.
Slower printing gives plastic more time to fuse with the layer beneath it. This often improves strength, especially for functional parts. However, printing too slowly can also cause problems. Excessive heat buildup can soften details, cause sagging, or lead to inconsistent extrusion.
Acceleration adds another layer of complexity. Acceleration controls how quickly the printer changes speed and direction. High acceleration allows rapid movements, but it also introduces vibration. This vibration shows up as ringing or ghosting on surfaces and can subtly distort dimensions.
Every time the printer accelerates or decelerates, pressure inside the nozzle changes. If this pressure is not managed correctly, it leads to over-extrusion at corners or under-extrusion during rapid moves. These effects are small but cumulative, especially in precision parts.
Modern printers use features such as pressure or linear advance to compensate for these pressure changes. These systems predict how filament behaves under motion and adjust extrusion accordingly. When tuned correctly, they dramatically improve consistency.
Speed should never be applied uniformly. Different features of a print have different requirements. Outer walls benefit from slower speeds to preserve accuracy and surface quality. Infill can be printed faster because minor inaccuracies are less visible and less critical.
Bridges and overhangs require careful speed control. Printing too fast causes sagging, while printing too slowly allows plastic to droop. Matching speed with cooling is essential here.
Cooling itself must be considered alongside speed. Faster printing generally requires more cooling to prevent deformation. Slower printing often benefits from reduced cooling to improve layer bonding. Using the same fan settings for all speeds is a common mistake.
Material choice also affects optimal speed. PLA tolerates faster printing than PETG or ABS. PETG prefers slower, steadier motion to avoid stringing and weak bonding. ABS and ASA often require controlled, moderate speeds to maintain dimensional stability.
Speed settings influence print reliability as much as quality. Aggressive speeds increase mechanical stress on belts, bearings, and motors. Over time, this reduces consistency and increases maintenance requirements.
Professional printing does not chase the fastest possible result. Instead, it aims for controlled motion that produces predictable outcomes. A print that finishes an hour later but works correctly is far more valuable than one that finishes quickly and fails.
At BritForge3D, speed and acceleration are tuned per material and per application. Functional parts are prioritised for strength and accuracy, while visual parts are tuned for surface finish.
Understanding speed as a tool rather than a shortcut changes how you approach printing. It allows you to make deliberate decisions instead of relying on guesswork or presets.
Once speed and motion are under control, the printer becomes more than a machine — it becomes a predictable manufacturing system.
Guide 5 Summary – Print Speed, Acceleration, and Motion Control
This guide revealed why print speed is not just about saving time. You learned how speed, acceleration, cooling, and material flow interact to influence layer bonding, surface finish, and dimensional accuracy.
By treating speed as a controlled tool rather than a shortcut, you can produce prints that are both reliable and efficient. Understanding motion control helps reduce failures and improves consistency across prints.
The next guide shifts focus to appearance, exploring how surface finish and post-processing techniques turn printed parts into professional-looking components.
