You can surely engrave PU leather but, it is recommended not to engrave the PU leather unless you have an air purifier or a fume extractor. PU leather contains polymer which releases toxic fumes while engraving.
In this article, we will explain what PU leather is, and how many variations of PU leather are there, and will suggest how can you laser engrave the PU leather.
What is PU leather?
PU leather, also known as polyurethane leather, is a synthetic material designed to mimic the look and feel of genuine leather without utilizing animal hide. It’s a popular alternative for those seeking vegan-friendly products or more affordable options than real leather. In a nutshell, PU leather is an artificially made or modified alternative to genuine leather.
Imagine you’re shopping for a new wallet. You find one that has the sleek, polished appearance of leather, but the price tag is surprisingly low. Upon closer inspection, you notice the label reads “100% PU leather.” This wallet is made from a backing layer, like cotton or polyester, coated with a flexible polymer, and then treated to look like animal leather.
How many types of PU leather are there?
There are three types of PU leather, each varying in quality, durability, and appearance:
Standard PU leather
This is the most common form, used in everyday items like shoes, bags, and furniture upholstery. It’s lightweight and easy to clean but may crack or peel over time.
Bi-cast PU leather
This type has a split leather backing covered with a PU layer. It’s glossier and has a more consistent texture but is less durable than top-grain or full-grain leather.
Microfiber PU leather
This high-grade type involves combining microfiber bundles with PU. It’s more expensive but also more durable and breathable, often found in premium products.
The main differences among these types of PU leather lie in their composition, manufacturing process, and intended use. Standard PU leather is your go-to for most budget-friendly items, while bi-cast PU leather offers a more uniform finish at a slightly higher price. If you’re looking for something that offers closer durability and breathability to genuine leather, microfiber PU leather is the best choice, albeit at a higher cost.
Why leather laser engraving is challenging?
Laser engraving leather is an art that combines modern technology with traditional craftsmanship. The process allows for intricate designs and precision that hand-tooling can’t easily achieve. However, it does come with its tricky parts that can impact the result.
In summary, the major challenges in leather engraving are:
- Inconsistent heat
- Improper laser settings
- Contains petroleum ingredients in leather due to the tanning process
One of the trickiest aspects of laser engraving leather is managing the heat produced by the laser. Leather is sensitive to heat, and if the laser is too hot or moves too slowly, it can burn the leather beyond the intended design, causing unsightly marks or warping. For example, in 2023 while engraving a wallet made from artificial leather using a diode laser, we kept the laser power high at 55% with a slow engraving speed (50 mm/s). The result was frustrating. We damaged the entire outlook of the wallet.
Then we rectified our mistakes and here’s the revised wallet engraving result:
Another challenge is the inconsistency of leather as a material. Leather isn’t uniform; it has different textures, densities, and natural imperfections, which can affect how the laser engraves across the surface. More importantly, leather sometimes absorbs water from the air moisture which directly affects the engraving just because the water element disrupts the laser beam sometimes.
Think about engraving a personalized name onto a wallet that has a mix of smooth and pebbled textures. The smooth areas might engrave crisply, while the pebbled sections could result in a patchy or faint output because the laser reacts differently to the varied textures.
Moreover, Choosing the correct settings for the specific type of leather is also crucial. Different leathers—be it cowhide, lambskin, or PU leather—react differently under the laser. Just like how a delicate fabric requires a gentler wash cycle, softer leathers need lower power settings to avoid burning through, while tougher hides might need more power to achieve a clear engraving.
Once we mistakenly chose a different image mood from Lightburn and the only settings destroyed our laser engraving.
Surprisingly, the natural oils and tanning processes used in leather production can cause inconsistencies when laser engraving. For instance, if you’re working on a full-grain leather belt, the natural oils may cause the laser to create a darker and possibly smudged impression in some areas, while areas with less oil might have a lighter engraving.
What are the best Lightburn settings for engraving PU leather?
The basic thumb rule of engraving laser is to avoid high temperatures and slow engraving speed.
We suggest keeping the laser power at 20% at max with maximum engraving settings (possibly more than 200 mm/s) along with the scan interval or a fill density of 0.1 mm.
Primarily, you should target a single-pass engraving since the laser does not usually require multiple passes.
You may have a look at the Lightburn Canvas settings guideline to learn more, but the above settings we found best for normal leather.
In the case of PU leather, you may lower the power a little bit by having a high engraving speed.
PU Laser engraving tips
First of all, you need to ensure that your laser engraver has a fume extractor or you have a proper air ventilation system. Since PU leather contains polymer, it releases harmful toxic gas while getting burnt. An air purifier or a fume extractor would help you not inhale those toxic gases.
Not all laser engraver comes with an air purifier; however, we found that this canopied laser engraver works well with leather.
Here are some other tips in case you are engraving PU leather:
- Choose the right laser machine. For the PU leather, diode lasers are okay to go with.
- Always test the settings before starting the actual job. Here’s a trick, if you are engraving a wallet, try to engrave something small on the deeper side. You may place a thin stainless steel piece underneath so that any excessive power does not mark the opposite side.
- After engraving, do not wipe it with clothes or any liquid cleanser as it will keep staining. Try using a soft dry brush to first remove those ashes.
- Always use an air-assist kit while engraving leather. It will keep the smoke away and protect the leather from over-burning.
- Use masking tape to ensure the laser beam does not leave any side burn while engraving.
Leather laser engraving would require sufficient knowledge of laser settings. Be aware of the different types of the leather and apply the accurate settings always.