Of course in Catholic Schools the nuns relished the idea of using chalk boards. They could enjoy sending kids outside to clap the erasers for cleaning, they loved getting chalk all over their outfits (I swear, they LOVED it) and they could take their fingernails and drag them down the board to wake you up. And even if that sound didn’t inherently bother you, the nuns found just the right pitch to get into your spine, too!
Boy, this thread did drift, but I gave a pretty good cite, so I am excused! No eraser clapping for me!
I’m a teacher too, and I’m going to disagree with this. As long as the whiteboards in our classrooms get cleaned regularly, they erase waaaaay better than chalkboards. It’s only when the residue or whatever is allowed to build up for weeks that it gets hard to erase, but even then I just clean it with some windex and it’s like new again.
I absolutely dread working in a classroom with a chalkboard. Maybe it’s the chalk we have–it’s labelled ‘dustless chalk’, but it is the dustiest thing I’ve ever seen. A puff of white smoke comes out just by opening the box, and that stuff gets everywhere. And when it does, it dries out my skin terribly. I wash the board with water before class to get rid of the white film, but it doesn’t matter-the board is disgusting again halfway through class.
Are you suggesting that they are literally glass because they occasionally break like glass, or are you being sarcastic? Green chalk boards are clearly ceramic, but I don’t know what kind. I’m watching this thread to find out.
I missed this. I have very strong opinions about whiteboards in chemistry departments. They are the absolutely worst thing a chemistry department can invest in. In a lab, they are effective for about a year before someone tries to erase year-old marks by wiping it with acetone. The acetone immediately disolves the dry-erase protective coating turning the previously useful dry-erase board into a markingboard-that-only-erases-with-stronger-and-stronger-solvents. After five years a pressure washer loaded with carbon tetrachloride is needed to create a useful writing space.
Even in the confrence rooms, marks are routinely left up for weeks at a time. They don’t erase with the erasor, so the first thing a chemist grabs is a bottle of acetone from the lab next door. Even when the board is never subjected to this treatment, the markers dry out every week. So every time the board needs to be used, you are stuck with a barely visible green marker to explain complex structures.
Invest in large signs that say “Don’t clean with acetone?”
Just let everyone know only to use the bottle of cleaner that comes with the boards/markers.
Besides, chalk makes dust, that dust can get into computers, or into those crazy chemicals you use in your labs, or what have you. Also, a lot of people are sensitive to it.
When they’re used in restaurants, somebody eventually tries to clean the board with one of those green ScotchBrite dish scrubbers, leaving an abraded spot that, once written on, is no longer erasable by any means.
Problem is, in my experience that little bottle runs out or gets lost and nobody can remember/be bothered to buy a new bottle.
*Blackboards were originally made of smooth, thin sheets of black or dark grey slate stone. Modern versions are often green or brown and are thus sometimes called a greenboard or brownboard instead.
A blackboard can simply be a piece of board painted with matte dark paint (usually black or dark green). *
I.e. yes you could have any color you want because it’s the paint, not the natural color of the material. And that’s why in many schools, the boards look new each year—they merely added a layer of paint. I’ve seen boards where someone left cello tape on it, didn’t notice till painting, and it was painted over.
WRT why those colors are more popular, I got nothing except it’s the contrast. If you had black chalk, maybe white paint would be fine.
Yup, I was gonna say this. I’ve only come across dry-erase boards in college, but there never, ever was a good marker. Ever. We had to try and read faded red or half-assed blue on white, and of course the old markers always made noises like fingernails on a blackboard. Very annoying. Chalk doesn’t dry out.
I also have not-so-fond-but-still memories of being the target of ballistic chalk from a history teacher, but a marker ? Now that would be hazardous thrown across a room
OK, just another memory here about chalk and erasers in Catholic school.
Does anybody remember putting a piece of chalk in between the sections of eraser so when Sister Mary *****(Cleophus, Madonna, and Lawrence all come to mind) went to use it it would make sideways chalk lines rather than erase? I’m laughing now just thinking about it. The nuns never seemed to get the joke though.
Similarly, in 1936 and '37, RCA built 200 test sets for company personnel to tune in the new NBC TV station. They used CRTs that registered - like oscilloscopes, FWTW - in shades of green.
I’m not sure if there’s a special state law that permits it, but the nearby village of Frankenmuth, Michigan, actually uses European-style signs for everything. The typeface, colors, shapes, everything. They’re not decorative; other than the speed-limit signs on the way into the city, there’re no other US-style traffic signs.
A sign that says “don’t use acetone” will quickly be ignored. Sure, the older students might know better, but the guard changes in grad school so often that little useful information gets passed down. Acetone bottles are scattered around any synthetic lab for the explicit purpose of cleaning organic residue. When your writing on the board, your activily focusing on the subject. Grabbing the acetone bottle is pure instinct.
Chalk is the least of our worries in a chem lab. It doesn’t stay in the air long and even if it gets into your reaction is not soluble and usually dry. Even so, if random stuff is flying into your reaction, your methodology needs work. I knew a guy that had his laptop flagged at the airport because it tested positive for nitrates. Chalk is least of our worries in a chem lab.
Here’s a dirty little secret: There is exactly one compound that you should ever use for cleaning whiteboards, and never use anything else. That one compound is good ol’ DHMO. Anything else at all, including the stuff sold specifically for that purpose, will start you down the cycle of having to always clean them with solvents. The companies that make the solvents know this, but they approve of it, the same way that a drug dealer approves of the fact that his product is addictive.
As for the preference for whiteboards or chalkboards, it seems to be a generational divide (coincidentally, at least among physicists, almost identical to the FORTRAN/C generational divide). You’ll prefer whichever you’re used to, and folks over a certain age are mostly used to chalkboards, while younger folks are mostly used to whiteboards.
When I was a kid, “glass” was sort of a kiddie folk term for ceramic or porcelain. At least, I remember several of my friends talking about how they had a fragile “glass doll” that they weren’t allowed to play with. And, much to my disappointment, said dolls weren’t actually glass–that wouldn’t have been mundane enough.
I don’t remember any little kids talking about ceramic or porcelain objects at all–to many of my peers, all ceramics were either china or glass.
As a side note, I normally hate writing with chalk on a blackboard, but I love using chalk on black laboratory bench tops, which are either slate or some sort of resin. They’re smoother, and the chalk glides better, and I really wish that blackboards had that texture instead.
In China I’ve seem chalkboards that were painted on mirrors. I have no idea why that is, but at least we know it’s true that someone somewhere uses glass to make chalkboards.
I think chalkboard-whiteboard preference just depends on what you are used to. I started teaching on chalkboards. It took some time to get used to the feeling of chalk on my hands, but nowadays I find they are actually quite pleasant to use and would much rather use that than deal with empty bottles of whiteboard cleaner and dried up markers.
When they are new, your erasers virginal, and your markers just out-of-the box, nothing beats whiteboards.
However in less-than-perfect circumstances there’s nothing like a good chalkboard and high-quality chalk. Thre’s never the problem of drying, dripping or staining. Also, good chalkboards last forever. You also have access to much more colours.
That’s really the problem with whiteboards. They work great under ideal conditions, but otherwise the markers dry out and the board gets stained. This might work great in a board room where everything gets erased regularly and there is always a fresh supply of markers, but I’ve never seen such conditions. In a lab, we will routinely leave common figures and notes on the board for years. It never gets erased until you need the space and by that time it’s stained so you need a cleaner other than water. In the conference room, the markers are always dry and the boss never buys new ones because they will be dry in a week.
The only positive aspect of whiteboards is the ability to project Powerpoint presentations on them.
Funny but true: an 18-year-old kid at work spray-painted his entire pickup truck with black chalkboard paint, and gives people chalk to write all over it.
…until an idiot co-worker forgets herself and writes on one with a permanent marker, then decides to fix her mistake by spraying the whole whiteboard with bathroom cleanser and scrubbing well, and then, when that fails to work, deciding, for reasons beyond the ken of man, to try kitchen cleanser instead.
Not that I am bitter.
By the way, best solution I’ve yet found for the Oops That Wasn’t A Whiteboard Marker Syndrome: as soon as you’ve discovered the mistake, take an actual whiteboard marker and scribble all over the writing, then wipe. Repeat as necessary. The solvent in the whiteboard marker will also help dissolve the permanent marker ink.
But I still prefer a good old-fashioned chalkboard. It’s an aesthetic thing.
And I am enjoying the discussion, thread drift and all.
