Label the skeleton

April 1, 2024 1:02 PM

Our goal is to put durable labels on a high-quality plastic teaching skeleton to help anatomy/physiology students. How best to go about it?

Paint markers will eventually wear off, and so will Sharpie. Dymo labels are too big and printing anything on regular paper or sticker paper is too fiddly. I am this close to getting very tiny labels printed on vinyl but I don't want to spend money if it won't work. Also, they would prefer something that doesn't change the overall texture of the skeleton (the tactile elements of the skeleton as it is are very important when the students are studying it.) The skeleton will need the names of the bones as well as specific sites of interest, so it's multiple labels per bone.

The person who owns the skeleton says the result of using one of those vibrating hand engravers/rotary tool engraving bits looks bad. I was thinking a scrimshaw technique with a hand graver/needle-in-a-holder plus an ink but I'm not sure how to go about it. It's one of those things where we have to do it in one shot and not mess it up, since it is hard or impossible to get exact replacement parts for a mid-range teaching skeleton. How do we label this skeleton?

posted by blnkfrnk to Grab Bag (17 answers total)

I would probably go for the Brother P-Touch label maker and the 9mm wide black-on-clear tape. These are quite sticky, thinner and more flexible than Dymo labels and can be put on mildly curved surfaces, you can produce the labels quickly and accurately, and the letters don't fade or rub off as they're under a laminated clear layer. You can even cut them narrower if you have very tiny things to label.

Alternative is to just laser print everything on regular paper, then cut to shape and glue down with something like rubber cement, then go over the top of it with clear nail polish.

Clear nail polish over the sharpie would last longer than bare sharpie too...
posted by seanmpuckett at 1:29 PM on April 1, 2024 [5 favorites]

Yeah the P-Touch makes extra sticky tape too. Is the skeleton bone? Potassium Permangenate stains bone dark brown. When you say paint markers, do you mean like Posca or like oil-based paint pens like an UNI Paint Marker?
posted by Iteki at 1:42 PM on April 1, 2024

The traditional way was India Ink. A layer of spray lacquer would make it last longer
posted by H21 at 1:47 PM on April 1, 2024 [4 favorites]

What about simply putting a number on each part of the skeleton you want labeled and have a laminated sheet with the details for each number hanging from the skeleton and a few extra in the room?
posted by JohnnyGunn at 1:52 PM on April 1, 2024 [3 favorites]

I use super glue to repair plastic and natural skeletons, and it holds both very well. Maybe small labels adhered with super glue?

If the skeleton has been handled a lot, I would consider washing it with a mild dish soap solution and then rinsing and drying. Oils from hands build up and make adhering anything very difficult. This tends to be worst with plastic bone models and less of an issue with natural bone. (I often use masking tape to make temporary labels for anatomy lab exams, and when it won't stick, a soapy wash in the sink helps immensely.)
posted by cyclopticgaze at 2:10 PM on April 1, 2024 [1 favorite]

Oil based Sharpies are significantly more durable than regular ones.
posted by metasarah at 2:50 PM on April 1, 2024

If you go the label printer route, Epson label printers apparently produce a more durable label than the Brother ones, although the tape is more expensive and they're bluetooth devices rather than handheld.

Personally, I'd take the whimsical route and attach little strung tags with handwritten labels. It adds a tactile element - the student has to pick up the tag to read it. Maybe put a QR code on the back linking to the relevant course material or Wikipedia page or something.
posted by pipeski at 3:01 PM on April 1, 2024

Could you laser engrave each bone?
posted by Jon_Evil at 7:01 PM on April 1, 2024

Response by poster: Yes-- Posca water based. Hadn't looked at oil based. Skeleton is some kind of hard plastic, definitely not actual bone, though it looks and feels very close. The school is ordering a new, unhandled skeleton.

How well do labels stick over 3D surfaces? Also, can you just hire someone to laser engrave stuff? Can it do plastic without melting? What's a fair price for lasering a skeleton?
posted by blnkfrnk at 7:13 PM on April 1, 2024

I would go with Sharpie which will drop into the acrylic of the plastic and seal with a spray acrylic varnish in two light coats. Clean after every semester with a damp cloth and reapply another coat of spray varnish. The varnish will take most of the wear from being handled and protect the writing.
posted by effluvia at 7:37 PM on April 1, 2024

A blue laser and a near infrared laser will not work on light coloured plastic. The energy just diffuses and at high power levels just melts the plastic. A CO2 long wave laser will work but will not leave a visible mark, you need to fill in the etched/engraved letters with paint. And you would have to seal it anyway. And you can feel the letters.

I tried this in my studio with actual plastic on actual laser cutters before I answered above.
posted by seanmpuckett at 3:28 AM on April 2, 2024 [2 favorites]

Don’t use spray varnish, the overspray will be annoying. Regular gel medium in gloss is brushed on and dries transparent. It’s acrylic and can be found in any art supply store. (They should have samples on display and maybe you’d prefer the matte). If you are putting it over ie a laser or inkjet printed paper, test first to make sure it doesn’t smear. It also works as an adhesive.
posted by TWinbrook8 at 4:19 AM on April 2, 2024

I don't know anything about skeletons but i do know a lot about getting things to stick to other things! Plastics are very difficult to get things to adhere to, either ink or adhesives. The usual trick is to sand the area you want to work on with an extremely fine-grit sandpaper (like 800 grit) and then write your thing (and cover with a clear-coat) or stick your label. Wear and tear, however, are still going to be an issue over time.

Alternatively, your initial idea (hand-engraver plus ink) would almost certainly work quite well—the engraving would substitute for roughening the plastic with sandpaper, and it'd be more durable (and you can always replace the ink if it gets worn off by handling). Sharpies would probably be ideal as the ink here, actually! Here's the thing i'd try: do your hand engraving, then simply write over the engraving with the Sharpie. While the ink is still wet, lightly wipe the surface with your finger or a tissue, and the ink should stay in the crevices while coming off the surface. Cover with a clear coat and then lightly wipe with a tissue again.

In either case, i second TWinbrook8's suggestion of an acrylic clearcoat rather than actual varnish. However, i wouldn't use gel medium, i'd use something with more flow. A 4oz bottle of plain "satin acrylic topcoat" should set you back no more than ten bucks at Michael's or equivalent art store—the cheap stuff is fine here! (DecoArt is a pretty cheap brand that i use a lot and love.)

Also: a cursory internet search suggests that most plastic teaching skeletons are made of PVC (which makes sense, it's one of the most common and durable rigid plastics). The great news about this is, you can get an experimental sample from any hardware store, in the form of PVC piping. Grab a couple 2' lengths of pipe, which will cost you about $8, and you have perfect specimens to try different things on until you find something that works for you!
posted by adrienneleigh at 1:15 PM on April 2, 2024

Another idea I had was to use little alphanumeric leather punches to deboss (indent) the plastic, rub in a bit of paint, sand/wipe off the excess, then clear coat as above. Less expensive than a laser engraver, just as durable, and easier to read and faster than a hand engraver.
posted by seanmpuckett at 3:25 PM on April 2, 2024 [1 favorite]

UV ink printing may be the right technology. There are pad and inkjet possibilities. Here is an example of printing on golf balls.
posted by Sophont at 3:52 PM on April 2, 2024

The skeletons I buy from 3B and Axis come premarked with numbers and a key. That works very well for students—they can use the models to test memorization, as the names of the parts aren't on the parts.

The numbers are very durable. I've had to reink a few and I used a Staedtler permanent pen, which hasn't rubbed off yet.
posted by Wilbefort at 12:32 PM on April 3, 2024 [1 favorite]

Response by poster: I think we are going to go with oil-based paint pen, a clear coat, and numbers corresponding to a key.

Does anyone know a good brand for both of those things?
posted by blnkfrnk at 10:42 PM on April 7, 2024