How to Choose Build Plate for Your 3D Printer

3D printer build plate, also known as print bed surface, is one of the basic components on a 3D printer that adheres and supports the bottom layer of printed objects. Bottom layer, as the foundation of a 3D printed object, is a crucial factor that decides if the whole thing piles up layer by layer successfully. A better build plate provides stable and solid support, flat and smooth surface, and meanwhile better adhesion for the bottom layer of your print.

Nowadays, there are a lot of different types of build plates on the market, for example, a glass or tempered glass plate, a polypropylene plate, a smooth or textured PEI sheet, or a PEX build plate. Here in this article, we'll discuss over build plate types and learn how to choose the best 3D printer build plate for specific 3D printing project.

Why Build Plate is so Important for 3D Print?

Why build plate is so important for 3D print? A build plate is not only a flat surface for melted filament to deposit, but also the platform provides heat and adhesion for the bottom layer of your 3D print. Another thing is the surface quality of the build plate. If a build plate has a smooth surface, you got a smooth bottom layer; if it has a rough surface, you got a rough bottom layer but much better bed adhesion.

Simply to put, a build plate affects the quality of the bottom layer of your 3D print greatly. If the bottom layer goes wrong, a lot of issues will happen to your whole print!

Popular Build Plates Types

On the market, we have various options over different build plate types, such as glass or tempered glass plate, polypropylene sheet, smooth or textured PEI sheet, PEX type build plate, and etc. Let's proceed to know them one by one. 

Glass Build Plate 

Glass build plate is the most commonly seen build plate on the market, especially on budget 3D printers for its lower cost but great compatibility with PLA printing. For example, the oringinal Creality CR-10S build plate is a glass sheet. 

A glass build plate has its own and unique advantages. It won't expand when heated. This decreases dimensional inaccuracy of your print. And also the smooth bottom of a glass print bed offers your print with similar smooth bottom layer.

The Ultimaker S3 and S5 3D printers are typical examples of glass build plates.

Pros & cons of glass build plate:

Tempered glass build plate

Tempered glass build plate is stronger and more durable than common glass bed. Being pre-stressed or tempered, this kind of build plate has stronger structure and can withstand impact shocks far better than regular glass. 

We can see tempered glass build plates on either a Kingroon KP5L or a Creality Ender 3 3D printer.

Meanwhile, with special coated surface, tempered glass build plate offers more adhesion to melted filament. 

Pros and cons of tempered glass build plate comparing with common glass print bed:

Polypropylene (PC) Build Plate

A polypropylene build plate is of course made of polypropylene, a kind of thermoplastic that makes the plate partially bendable, and we often call it PC build plate for short.

As a plastic sheet, PC build plate adheres filaments (which is also made of plastic) better than any other types of build sheet. This feature makes a PC build plate also a good surface for beginners in 3D printing.

Pros & cons of polypropylene build plate:

PEI Sheet

A PEI sheet for 3D printing is often made of spring steel and coated with polyetherimide (PEI for short) powder on its surface, either smooth or textured.

PEI sheet has strong adhesion properties and chemical stability that makes it a good option for FDM 3D printing. Prusa 3D printers are big fans of spring steel PEI sheets.

Smooth PEI sheet offers glossy bottom finish for your print while textured PEI sheet provides relatively more adhesion and a textured bottom finish.

In addition, a double sided PEI sheet can be smooth on one surface and textured on the other surface.

Pros & Cons of PEI sheet:

PEX Build Plate

PEX build plate is similar, yet superior to PEI sheet because of its much thicker coating and higher temp resistance.

A PEX build plate has a higher glass transition rate and higher melt point than PEI sheet, which allows it to print high temp filament like PETG without worrying about the surface bonding with deposited filament.

Pros & Cons of PEX build plate:

Other popular names for build plates

You may also hear other popular names of a build plate, such as flexible build plate, magnetic build plate. These names usually describes other features of a build plate rather than material related performances.

A flexible build plate means it can be bent for much easier printed item removal. Usually, a spring steel PEI or PEX build plate is a flexible build plate; and a PC build plate, which can be partially bent, to some extent, is also a flexible build plate.

A magnetic build plate is developed with magnetic characteristics to adhere to the print bed. Usually, a magnetic build plate is flexible.

For example, some popular 3D printers like Kingroon KP3S, Creality Cr-10 and Cr-10s are using magnetic removable build plates.

Guidance for printing on different build plates 

Undoubtedly, different build plates have different mechanical properties, heat conductivities, adhesion properties, and etc. And below tips might help you with a good start. 

Guidance for your reference: 

Glass build plate
Recommended material: PLA, ABS, PETG, TPU, nylon
PLA, bed temp 60℃; moderate gap 

PC build surface
Temperature tolerance: about 120℃
Recommended material: PLA, ABS, PETG, PC, TPU, nylon, polypropylene
PLA, bed temp 40-60℃; moderate or a little higher gap;

PEI build plate
Recommended material: PLA, ABS, PETG, TPU, nylon
PLA, bed temp 70℃; small gap
PETG, bed temp 70℃; moderate gap

PEX building surface
Recommended material: PLA, ABS, PETG, TPU, nylon
PLA, bed temp 70℃; gap as tight as possible for full filament flow
PETG, bed temp 70℃; moderate gap; hot end 240-250℃ to avoid fusing with surface

Note: above guidance is for reference only; settings may change according to different material qualities, printers, conditions, and etc.

How to Get Better Build Plate Adhesion

When 3D printer filament won't stick to bed or stick poorly, it can be caused by dirty build plate, not well leveled hotbed, inappropriate Z offset, inherent cons of materials or build plates, or sometimes the special structure of the object you're going to print.

1 - Clean the build plate
When poor build plate adhesion happens, check if the build plate has filament residues or excessive glues on its surface. If so, clean the build plate first. For stiff surface like a glass bed, you can use a spatula (usually come with the printer) to shovel filament residues off and wipe the surface clean with a soft cloth; for too sticky residues or on soft surfaces like a PEI sheet, you can apply some isoproply alcohol on and soak the residues soft to remove them.

2 - Re-level the printer bed

Incorrect bed leveling is another common cause of poor build plate adhesion. You can do bed leveling test printing first and then decide whether to re-leveling your printer bed.

Bed leveling test print: https://www.thingiverse.com/thing:2187071

For how to level your 3D printer bed, you can visit: https://all3dp.com/2/3d-printer-bed-leveling-step-by-step-tutorial/

3 - Adjust Z-offset value

Z-offset value is a crucial factor in FDM 3D printing. It depicts the distance from the nozzle to the home position of the Z-axis. If Z-offset value is wrong, the nozzle can be too far or close to the build plate, hence poor bed adhesion happens.
To find correct Z-offset for your 3D printer needs repeatedly try higher or lower values and consumes a lot of effort. But it's worthy for excellent outcome of your prints.

4 - Use solid glues or tapes

For a smooth surface like a glass bed, the inherent nature provides it a relatively poor adhesion. At this circumstance, some solid glue or tape onto the build plate can be a good solution.

5 - Set brim or raft while slicing

Some objects have low adhesion to the build plate because of their bottom layer have less contact with the bed. And slicer default setting can be skirt, but skirt doesn't help in bed adhesion. For these objects, we can alter to brim or raft to assist with better bed adhesion.

6 - Adjust bed temperature

Incorrect bed temperature affects bottom layer adhesion too. Too high bed temperature leads to sticky bottom layer to the surface while too low bed temperature results in warping. You can do test print and try rise bed temperature by 5 degrees Celsius per time until you find the most appropriate bed temp for your print.

7 - Alter first layer printing speed

The first (initial) layer printing speed affects bed adhesion too. Try alter the setting by slowly raise or drop the value when previous steps do not solve your problem.

8 - Replace the build plate

The last thing to improve build plate adhesion is when we find flaws (uneven surface, residues unable to remove or deep scratches) on the build plate itself, just replace the old one with a new build plate.

Some build plates just don't fit for some filament types, then you can replace it with a new build plate which fits the material better.

Final Suggestion on choosing 3D printer Build Plate

Choosing an appropriate build plate for you daily 3D printing is actually not a simple task to do, especially when you're not familiar with a new type of build plate. The above descriptions over the features of different build plate types and their pros and cons are basic knowledge you should know before you make a pick.

To find out the best build plate on your own, it's better to consider all the factors mentioned in this article, and then decide which one or two might be suitable for you. The next step is to experiment with the new build plate you're going to use. This will help you understand bed adhesion and material interaction better and make your final decision more rational.