Laser engraving tiny text successfully

Laser engraving tiny text successfully

Posted Posted in How to, Wood

Maggie’s Fife is a much loved local charity that supplies practical support to cancer patients, helping sufferers with advice on everything from wigs to insurance, and how to explain things to families and friends.

Tu, their Centre Fundraising Manager got in touch. She wanted to create some baubles that people could sponsor as a Christmas fundraising campaign and wondered if we could create something together.

Bauble artwork

Tu wanted a bauble shape with the Maggie’s logo in the centre. She sent me a black and white pdf which was perfect for my needs. She also found artwork for a bauble shape she liked that was free to use and asked me to make the bauble shape 7cm in diameter.

After some feedback on an initial prototype, Tu sent a snowflake shape that she wanted dotted around to add more interest as the baubles looked a bit bare. To add variety, I suggested that I could vector engrave them. As vector engraving is more efficient than raster engraving, it would help to keep the cost down too. I added three snowflakes, resized and slightly rotated so they’d all look different.

Tu loved the proof, approved the quote and asked me to make an initial production run to get them started.

How to engrave tiny text

I knew that the biggest challenge with the baubles would be engraving the second line of text in the logo, ‘Everyone’s home for cancer care’.

When any artwork is miniaturised, whether logos or anything else, all details become smaller. It can be difficult to get good engraving resolution. In cases like this, I always do tests to ensure I’m happy with the results. If I’m not, I’ll offer solutions which can include enlarging or tweaking the problem details. Elements can be deleted altogether, or the whole product can be enlarged.

In this case, slowing the engraving speed significantly was enough to do the trick, along with selecting the right power so the text was clear, but not too heavy.

The E of ‘Everyone’ is just under 2mm high, and the smaller letters are just over 1mm high. They’re the smallest text I’ve engraved I think! It helped that the of the font was fairly bold to start with.

Tu wanted 50 baubles to start with, with the option to come back for more if they’re popular! If you’re interested in supporting the campaign, you can contact Maggie’s Fife.

 

Have you got a product you’d like to develop but aren’t sure how? Contact us or ask for a quote.

How to make giant protractors

How to make giant protractors

Posted Posted in How to

A customer from distillery cooperage contacted me. They needed to replace their giant protractor that they use for barrel making. Their old protractor had had a hard life and was getting very damaged as you can see below. It was becoming inaccurate and unreliable, so it was time for some new ones.

old distillery protractor
Old distillery protractor

Maximum protractor diameter

Two protractors were required at 1000mm diameter. My laser is bed is 1200 x 800mm which meant that the maximum diameter of protractor I could make was 800mm. The cooperage was was happy for me to make them at that size.

Robust materials

The coopers wanted something not too thick and heavy, but robust and shatterproof. It was also important that the degree markings and numbers should be easy to read.

My main suggestions for materials were plywood, mdf and perspex. Plywood is heavier at the same thickness of the other two materials. It’s more expensive and can shatter if dropped. Engravings on perspex are always white in colour and not as clear as engravings on ply and mdf. So we ruled perspex out for those reasons.

Next, I made sample engravings on ply and mdf and sent them for evaluation. As birch ply is lighter in colour than mdf board, it was the option of choice as the engravings were clearer on the blond wood.

To make the protractors as robust as possible whilst keeping them light and easy to use, the coopers asked for 4mm ply rather than 3mm.

Making the engravings stand out more

Artwork for the protractors was right first time. All the cut lines and the degree lines and numbers were a single line thick, and the laser vector engraved all of these, giving thin but clear marks. But the coopers asked if I could make the lines bolder.

I have a cunning way to do this. When the machine is properly focused on the surface of the material, the beam is as small as possible to give a clean cut or accurate engrave.

If the beam is defocused, the beam becomes wider and therefore engraves a wider vector engraved line. I made another sample to demonstrate this and the coopers gave the go ahead to make the protractors using that fix.

Laser cutting and engraving the giant protractors

I did this in two steps. First, I defocused the laser and engraved all the degree markings and numbers. Then I refocused the machine and performed the cutting as shown in the video above.  I did it that way round to ensure the plywood stayed as flat as possible throughout production. It’s easier to do this if the material stays as one integral sheet.

The ply for the second protractor that you see being cut in the video above was more inclined to warp, so I had to hold it flat by weighing it down with slates.

My customers were really pleased with their new protractors. I think they’re rather beautiful!

 

Have you got a product you’d like to develop but aren’t sure how? Contact us or ask for a quote.

Planning designs around materials

Planning designs around materials

Posted Posted in FAQ, How to

Sometimes, customers need guidance about the best materials for their projects. If we consider how products will be used and where they will be displayed, there’s usually a good solution.

Material properties

Plywood that has laminated layers. Mdf is pressed into fibre boards of different thicknesses. Both become stronger with increasing thickness. Even at 3mm, plywood’s laminated layers give strength in two dimensions. It’s ideal for making small pieces like keyrings and golf bag tags that endure heavy usage, and it’s cost effective too.

Oak can snap with the line of the grain when there are imperfections in the grain called shakes. Other solid woods don’t have shakes.

Perspex is very robust, but it can shatter when dropped or snap at narrow points. Its broken edges are sharp edges and they cut skin easily. They’re so sharp I haven’t felt injuries at the time.

Mylar and polypropylene are bendy and flexible and can be almost indestructible. I use polypropylene for ballet tutu templates that need to take being snipped against with shears, but can bend with the netting. Rigid templates wouldn’t work.

Design delicacy

If a design is delicate, then robustness needs to be built into the design to ensure it will perform. As a rule, I find that keeping narrow areas of a design to 2 to 3mm wide works with any material in most cases. Here are my top tips for designing artwork for laser cutting.

treated oak sign mounted on stone gateway

Will the products be handled?

If objects are to be handled, especially by children, materials need to be chosen with care.

Wood is chunky and light. I’ve made giant plywood and mdf jigsaws with FifeX and The Malting House Design Studio that have worked really well.

Coloured perspex models (pictured at the top), coloured Valchromat and foam are good options too, and extra pieces can be made just in case.

Outdoor display

Which materials will stand up to the weather or survive being mounted in the ground?

Green oak and green larch are ideal for outdoor use without any treatment at all. They’ve been used for building for hundreds of years and can survive in the ground for 20 years or more. They make great wayfinding posts, signs and plaques.

Other softwoods and hardwoods need varnishing every year or so to protect them from the weather. If there#’s no budget for maintenance, it’s best to choose a low maintenance wood. Green larch is a cost effective option if green oak is too costly.

Marine ply is suitable for outdoor use with treatment. Unfortunately, laser grade ply is indoor grade and will only withstand outdoor display with very regular treatment.

Perspex, on the other hand, is perfect for outdoor use. It’s weather proof, is UV stable and doesn’t rot.

Mylar and polypropylene are perfect for flexible stencils as they can be washed.

 

Have you got a product you’d like to develop but aren’t sure how? Contact us or ask for a quote.

tools of my trade calipers

Tools of my trade – calipers

Posted Posted in FAQ, How to

Where would I be without my trusty calipers? They might be small, but I use them every day and they allow me to double check within seconds how thick a material is.

With laser cutting, the principle is to cut at maximum speed and the maximum power required for that speed for a clean cut through. Machine settings I select for 10mm perspex are different to the ones I’d choose for 1mm card.

If a material is a bit thicker than expected, even by a fraction of a millimetre, the chances of not getting a clean cut through increase. As a result, materials and production time are wasted.

Sometimes, production is successful, but if cut parts are designed to slot into each other and are too thick or thin, fit is not good. There’s a case study about this here.

Solid wood

It can be tricky to get sheets of solid wood cut to an exact thickness as they need to be cut with a saw and sanded down. They always need to be checked and I sometimes perform test cuts before starting a job. And as each piece of wood is unique with slightly different densities, tests are a wise precaution anyway.

Wood isn’t made in a standard process like perspex is. Tree type, where the wood came from in the tree, its growing conditions and how the wood was processed can all affect how the wood behaves.

measuring calipers

Perspex

Perspex is usually pretty reliable in thickness as it’s either cast in sheets of a certain thickness, or it’s extruded through rollers set to a specified thickness. Some brands need to be cut a little slower than others. There’s a blog about perspex here.

Birch plywood

When I buy birch plywood, the thickness described is nominal, not actual.

Nominal 3mm ply is usually 3.1 to 3.2mm, and 4mm is often 3.8 or 3.9mm. As it’s made of laminated layers, final thickness of a sheet depends on the thickness of its layers.

Some thicknesses of ply can look similar to others. I regularly use 3, 4, 5, 6 and 9mm. Sometimes, I’ve selected a piece of 4mm instead of 3mm, or 5mm instead of 6mm by mistake. Measure twice, cut once as a wise person once said!

If I pick a thicker piece by mistake, I don’t get a clean cut. If I select a piece that’s too thin, the work can burn on the back.

Cutting a material too slowly with too much a power damages final product quality. So checking before production makes sure products are right first time.

 

If you’ve got any questions about laser cutting and engraving, contact us and I’ll do my best to answer them.

Can I raster engrave using vector artwork

Can I raster engrave using vector artwork?

Posted Posted in How to, Prototyping

A customer asked me this last week as we discussed her new product ideas and how to add detail to cut out shapes.

The answer? Yes, you certainly can raster engrave using vector artwork, but there’s one major pitfall to avoid.

There are two ways to create vector lines with any thickness. One works really well in all situations and the other works in some scenarios, but not others. I’ll show you why.

The problem: how vector lines are seen by laser software

This is the biggest thing to get your head around. Vector lines can be created and then made to look a certain thickness, anything from hairline to 2.5mm.

If you view the artwork as a simple wireframe, you see what my laser cutting software sees – a hairline line, however thick you may have made it appear. To raster engrave to get the same effect, I have to follow these steps.

Step 1: To raster engrave the area, I’d select the artwork element

Step 2: Convert the selected lines into bitmaps while leaving other lines as vectors. This keeps the lines at the thickness shown on the screen so they doesn’t revert to hairline thickness at step 3. All the other lines for cutting and vector engraving need to be in that format.

Step 3: Export the artwork with the different elements to my software that tells the laser what to do with the artwork.

This can work for simple designs, but it can be a nightmare with more complex ones. Following my fool proof method below avoids all these problems.

Fool proof vector artwork for raster engraving

Kate decided that she wanted to add raster engraved details to her laser cut goose shapes. Raster engraving was the look she wanted.

I asked Kate to imagine a thick black line, say 40mm by 5mm. To have this line raster engraved, I told her she’d need to create a box 40 x 5mm using vector lines. I’d instruct the laser to raster engrave that rectangle.

If each element she wanted raster engraved was outlined by a surrounding line, the areas inside those lines could be raster engraved. This is how I’d treat the green feathers in the artwork above. Or if Kate wanted them vector engraved, the outline lines could be line engraved. It’s an easy and flexible method.

Kate Millbank vector engraved goose

Engraved geese

As it turned out, Kate wanted children to paint the geese. I suggested that the raster engraved feathers could be lost under the paint. It would be a shame to make a more expensive product with detail that could be lost. Vector engraving would be cheaper than raster engraving and would create outlines that the children could paint in.

This was a perfect solution for Kate. She’d given me foolproof vector artwork, so all I had to do was code the feathers for vector engraving. The results are shown in the picture above.

 

Have you got a product you’d like to develop but aren’t sure how? Contact us or ask for a quote.

 

Other artwork blogs that might be useful:

Designing artwork for laser cutting

Designing artwork for raster engraving

Cutting and engraving using the same artwork

Are vector and raster engraving different

Designing artwork for raster engraving

Designing artwork for raster engraving

Posted Posted in Artwork, How to

There are two ways to provide artwork for raster engraving, the fill in engraving shown on the board engraved for the Royal Botanic Garden Edinburgh above.

Pixel based files

Pixel based files include png, jpg and bmp files. They must be provided in black and white at a print quality resolution of 300dpi or greater to ensure good quality engraving.  Any pixellation in the image is seen in engravings!

Sometimes, customers provide artwork from the internet. While these look good on a computer screen, they aren’t good enough for engraving (or printing) as they’re only 72 or 96dpi.

And if pixel based images are rescaled, they can lose quality and become pixellated the more they’re processed through resizing. All these potential problems can be avoided by using vector files.

Vector files

Vector files  include ai, pdf, dxf, eps and svg files. They are made up of vector lines, not pixels as png, jpg and bmps are. Artwork for the engraved board at the top was created by pdfs and is shown below.

A huge advantage of vector files is that they can be rescaled to the size a customer wants without loss of image quality. Files are rarely provided at the scale required for a job, which means that resizing a logo or other artwork is inevitable.

Vector files also need to be black and white with no greyscale.

 

Why black and white?

Lasers can’t engrave in colour. The colour of engravings depends on the colour that the material becomes when it’s burned by the laser at the speed and power selected. In the case of wood, you can get deeper shades of brown and greater depths of engrave with increasing power or reduced engraving speed.

As the laser either engraves or doesn’t engrave, artwork needs to accommodate this. Generally, I recommend that the parts of a design to be engraved are black and non engraved areas white. Shades of grey can be achieved with different densities of black pixels like old fashioned news print, and the black pixels will be engraved to give a grey effect.

Why doesn’t greyscale work?

When the laser sees a shade of grey, it decides whether it’s dark enough to be black and engraves it as black, or decides it’s light enough to be white and doesn’t engrave it.

 

Have you still got unanswered questions? Email me at jane@laserflair.co.uk.

Follow these links for my top tips for designing artwork for laser cutting and laying out vector artwork for laser cutting .