Re: poor man's decal

Don Y <blockedofcourse@foo.invalid> wrote:

On 4/2/2025 4:23 AM, Liz Tuddenham wrote:

Don Y <blockedofcourse@foo.invalid> wrote:
 

I need a full-color, durable decal to label a front panel.
The panel is ~8x17".  I'm only looking for prototype quantities
(someone else can deal with production quantities and "revised
artwork").
>
I think I can just color print the image, 1:1, laminate it
and use a spray adhesive to affix it to the actual panel.

 
For prototypes or one-offs, I print in mirror-image on an overhead
projector acetate sheet using a laser printer.  The print side is then
spray-painted white (several very thin coats, allowed to dry between
coats, so as not to dissolve the printing) and stuck to the panel with
double-sided sticky tape.

 
Do you cover the entire surface with tape?  Or, just the edges?

Usually the entire surface and a bit beyond, then trim off the excess.

Most of the double-sided tape I've used would have too much tack
if used to completely cover it; removing the decal would be tedious.

My experience has been that the weakest bond is between the print and
the acetate sheet.  Pulling the acetate sheet from a corner leaves a lot
of the paint and print on the sticky tape; some of the tape can be
removed mechanically and the rest comes off with solvent.

[I just want the decal to stick to the surface, now cling for dear life!]

On double-sided sticky tape it will - your biggest problem will be
getting it lined up before it sticks in the wrong place.  I have two
methods:

1) Put the tape on the panel, then use a soldering iron and/or file to
clear the tape from the holes where the control shafts and switches will
be.  By shining a light through the holes I can then line-up some +
marks on the print, which correspond to the hole centres, while I bring
the decal onto the sticky surface in exactly the right place.

2)  Put the tape on the panel etc as before. then line up one long edge
of the decal on the edge of the panel and let it touch.  The decal can
then be swung down, using that edge as a hinge, and carefull pressed
onto the panel starting from the hinge edge. 

Once it has stuck, any attempt to reposition it or remove any air
bubbles will probably finish up tearing the print off the back.

 

The unprinted acetate surface is fairly durable and the print side is
towards the panel, so it can't be scuffed off.

 
Yes, I took that approach with a digitizer overlay.  But, that's a pretty
gentle environment; you're never poking at it with anything that may
have an edge.

True, but i have known these acetate labels to survive nearly 5 years
outdoors on a south-facing wall (in English weather, which is not the
severest of UV tests).

If you need to change it, the sticky residue from the tape can be
removed with white spirit or petrol.

 
I was hoping to eliminate the use of solvents.
 
Many products, here, bear "printed labels".  Historically, these have
been paper; removing them is a chore as the label needs to absorb a
solvent to facilitate its removal (I use water, alcohol, mineral
spirits and, rarely, acetone -- as it often attacks the surface to
which the label is adhered).

The acetate sheet can be ripped off, so the solvent attacks the sticky
stuff fairly directly.

 
But, there are also similar labels printed on a plastic/nylon
sheet.  These can be removed "intact" -- with patience -- just
by getting a corner "started".  The adhesive used is weak enough
(and the label material strong enough) that it doesn't tear the
label as it is removed.  And, the printed content is well-bonded
to the substrate such that it doesn't require any additional
coating (or, that coating is applied in the process of making
the label).
 
So, I'll either print on paper and use a laminating *pouch* (so
both sides of the paper are coated in plastic instead of having
paper on one side) OR try mylar (or acetate) and hope the printed
material doesn't "linger" after the adhesive is released.

The acetate sheets are so cheap that it doesn't matter if you destroy
one when you remove it.  If they are not too big, you can also print
3-up or 4-up on an A4 sheet, so you can easily keep a few spares.

As I said in my post, it's just to get through prototypes so it
looks "professional" to VCs and is as *functional* as the real
decal would be ("How do you service this?  It seems awfully
costly to adopt a replace-as-FRU policy")

You can see a picture of the sort of results I have managed to obtain
at:
http://www.poppyrecords.co.uk/other/DistortionMeter/Manual.pdf


--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk