[Mikey Sklar] had a problem—namely, running low on the brass material typically used for making PCB stencils. Thankfully, a replacement material was not hard to find. It turns out you can use aluminum business card blanks to make viable PCB stencils.

Why business card blanks? They’re cheap, for a start—maybe 15 cents each in quantity. They’re also the right thickness, at just 0.8 mm, and they’re flat, unlike rolled materials that can tend to flip up when you’re trying to spread paste. They’re only good for small PCBs, of course, but for many applications, they’ll do just fine.

To cut these, you’ll probably want a laser cutter. [Mikey] was duly equipped in that regard already, which helped. Using a 20 watt fiber laser at a power of 80%, he was able to get nice accurate cuts for the stencils. Thanks to the small size of the PCBs in question, the stencils for three PCBs could be crammed on to a single card.

If you’re not happy with your existing PCB stencil material, you might like to try these aluminium blanks on for size. We’ve covered other stenciling topics before, too.

Sometimes you come across a purported scientific paper that makes you do a triple-check, just to be sure that you didn’t overlook something, as maybe the claims do make sense after all. Such is the case with a recent publication in the Langmuir journal by [Budlayan] and colleagues titled Droplet-Scale Conversion of Aluminum into Transparent Aluminum Oxide by Low-Voltage Anodization in an Electrowetting System.

Breaking down the claims made and putting them alongside the PR piece on the [Ateneo De Manila] university site, we start off with a material called ‘transparent aluminium oxide’ (TAlOx), which only brings to mind aluminium oxynitride, a material which we have covered previously. Aluminium oxynitride is a ceramic consisting of aluminium, oxygen and nitrogen that’s created in a rather elaborate process with high pressures.

In the paper, however, we are talking about a localized conversion of regular aluminium metal into ‘transparent aluminium oxide’ under the influence of the anodization process. The electrowetting element simply means overcoming the surface tension of the liquid acid and does not otherwise matter. Effectively this process would create local spots of more aluminium oxide, which is… probably good for something?

Combined with the rather suspicious artefacts in the summary image raising so many red flags that rather than the ‘cool breakthrough’ folder we’ll be filing this one under ‘spat out by ChatGPT’ instead, not unlike a certain rat-centric paper that made the rounds about a year ago.