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Eric's overlay - my experience and suggestions
Message #1 Posted by Cristian Arezzini on 18 June 2011, 12:53 a.m.

I received the WP34s overlays today, and I immediately went to install one. It's a great product and it has improved the looks and usability of my calc a lot. But being a "first run", I suppose constructive criticism is expected, so here are the (tiny) things I'd change. I'll describe them in the order I noticed them.

When I first touched the overlay, I had a feeling of "roughness" of texture. I was expecting something much more "smooth" at the touch, I don't know how to describe it better. I'm not saying I wanted something shiny... matte is ok. But passing a fingernail over the black areas encountered some resistance, as if the surface wasn't perfectly smooth; and it left a visible mark.

Then I proceeded to apply the top small sticker, the one saying "WP-34S RPN scientific". I peeled the sticker from the backing with tweezers, and it is much "softer", more flexible, than I thought. I thought it would be more "plastic-like". Being so flexible is better in a way because you can "stretch" it a little if needed; but on the other side, it could go on a little "deformed" if one is not precise (by the way: tweezers really are a MUST with this product).

Anyway, I went on with the main piece. One thing I already noticed from others' photos, is that I would really like if the corners could be rounded a little, especially the two corners on the bottom. On a 30b, where the contrast with silver is bigger, I think it would look better. Anyway, I followed Eric's suggestion of first sticking the middle part, and then proceeding towards the top and the bottom. It worked great, at the first try, no need to reposition it. All the keys "feel" OK, except the ENTER which seems a little more "murky". There's not much I can do to fix it, I suppose... I might try "filing" with a modeling knife around the key, but I fear it might look bad then. Maybe making the holes just a tad wider (just 1/10th of a millimeter maybe) could help...

Then, to help the adhesive stick better, I put a soft cloth over the calc and passed my fingernail all over the overlay, pushing down a little between the keys. And here is where the worst problem showed up... the whole overlay now shows "blemishes" where my fingernail passed. In those places it is shinier, less matte, than the rest of the black ink. So: don't even *try* passing a hard (or semi-hard) object over the overlay, if you want to keep it pristine. Even if you protect it with a soft cloth.

Then I proceeded with the keys. They went on without problems, I could place them all in their correct position and very neatly - many years of building small airplane models definitely helped here! :) But one thing I noticed is that the cut is deeper than the vinyl; and so sometimes, the tweezers "caught" on a layer of the substrate too, and it was difficult to separate the sticker from the backing. Eric commented that he could make the cut less deep, but that in this case it's better a little too deep than too shallow. Which of course makes sense. If it seems difficult to lift a key from the backing, just try at another side of the key.

I also noticed that the key stickers leave quite a large surface of the key uncovered - which is intentional, because if they were larger, then if a key went on not perfectly centered, a "lip" would remain out of the key, possibly sticking to something and making the whole sticker peel away.

In a couple of places (the ENTER key and the original SHIFT key) a little blue shows below the sticker. Eric says these two keys might be slightly enlarged to fix this.

So, to recap:

  1. - The ink's "texture" could be made a little smoother, "slicker" without having to be shiny, I don't know what exact words to use...
  2. - The vinyl is thin but that's just a "psychological" feeling, once it's on it's perfect. It seems really durable and "elastic".
  3. - It would be really nice if a way could be found to make the black ink more resistant to scratches/damages by fingernails or other semi-hard objects. I'd like to keep it matte though.
  4. - The corners (especially the bottom ones) could be rounded.
  5. - The key holes could be a tiny bit larger.
I still don't know about durability of course. I'm wondering if it will catch dirt/finger oil, and in case it does, if it's cleanable without damage.

If you want I can post a picture, which shows the marks left by my fingernail and the small blue parts showing below two keys.

There's something I'm wondering: does anyone have an idea of how many WP34s (I mean real, hardware ones) exist in the world? And how many have an overlay?


Re: Eric's overlay - my experience and suggestions
Message #2 Posted by Eric Rechlin on 18 June 2011, 9:58 a.m.,
in response to message #1 by Cristian Arezzini

It's not the black ink that isn't resistant to pressure smoothing it out making it shiny, it's the vinyl itself. The only solution I can think of is for me to spray the whole overlay with a glossy protective spray before cutting. Of course, it would then all be shiny, which would mean more glare. Not sure what you guys would prefer. I just don't rub my fingernail on my 34s and that way it stays matte.

The overlay is surprisingly safe from cleaning solvents. Water is no problem at all, and I even was able to wipe it with both isopropanol and brake cleaner with no damage, so you can use some fairly strong solvents. The only concern is abrasion, which would cause the ink to flake off, but I see this as being more of a problem on the edges of the labels rather than anywhere else.

I shipped about 60 overlays over a one-week period.


Re: Eric's overlay - my experience and suggestions
Message #3 Posted by Jim Yohe on 18 June 2011, 1:15 p.m.,
in response to message #2 by Eric Rechlin

Brake cleaner? There must be an interesting story for the reason you happened to try that out over the overlay. Perhaps there's a high percentage of auto mechanics who'd be using a WP 34s? ;-)

Re: Eric's overlay - my experience and suggestions
Message #4 Posted by Eric Rechlin on 18 June 2011, 1:54 p.m.,
in response to message #3 by Jim Yohe

I was just trying random chemicals that I had in my closet. :)

MAF cleaner didn't hurt it either.


Re: Eric's overlay - my experience and suggestions
Message #5 Posted by Marcus von Cube, Germany on 20 June 2011, 5:18 p.m.,
in response to message #1 by Cristian Arezzini

Mine have arrived, too. Thanks Eric!

My poor development unit in its new clothes.

This is my carry around 30b.

As you can see, the overlay is pitch black. I had some trouble with the f, g, and h prefix keys on my 30b which had lost the click. I must have glued the overlay too close to the upper edge of the keys. I solved it by introducing a sharp knife (the small blade of my Victor Inox pocket knife) in the gap above the keys. This seems to have widened the gap enough for a good key click. Over the second row from below you can see the bright background shine through. It might be worthwhile to paint around the keys with a permanent marker before applying the overlay.

Now let's see how long it will last.

Re: Eric's overlay - my experience and suggestions
Message #6 Posted by Gerry Schultz on 20 June 2011, 5:37 p.m.,
in response to message #5 by Marcus von Cube, Germany

I put my overlay on this weekend and it worked out much better than expected. One thing I found is that when I was putting on the key cap covers, if I put them on lightly, there was play in the adhesive and I could do final positioning by pushing and twisting on the cover to get them all aligned in rows and columns.

Overall it came out great and I'm very satisfied. Now I feel like I got a new calculator. That overlay sure make a big difference.

Thanks a million, Eric.


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