[mothered]

When first applied nothing just printed on the water solulable paper looks exactly same as normal paper

Sounds good.

The time for the ice to melt through to dissolve the paper would be a few hours maximum then the label would be gone 

This could be a problem for shipments with a greater storage time.

If the label disappears while the package Is still at the depot awaiting delivery allocation, It may be Identified against the details recorded on the manifest.

[Alekzen]

Did you figure out what technic to use ? did it work ?

[sinisterlee]

I’ve just come across blueplanet ink that offer self erasing ink have you used this before

Not from that supplier.

How long does It take for the Ink to completely disappear?

Care to share an alternative supplier?
Disappearing black ink would be ideal.

[Alekzen]

[/quote]
Disappearing black ink would be ideal.
[/quote]

I don't think black disappearing ink is actually possible. At least I haven't seen some.

But I read on a website that purple ink barcodes can be scanned. besides : I don't think the depot where you'll drop off you package will refuse it because the label is printed with purple ink.

Unless the couriers are very aware of this technique and kinda report it when they notice it ?

[sinisterlee]

Disappearing black ink would be ideal.
[/quote]

I don't think black disappearing ink is actually possible. At least I haven't seen some.

But I read on a website that purple ink barcodes can be scanned. besides : I don't think the depot where you'll drop off you package will refuse it because the label is printed with purple ink.

Unless the couriers are very aware of this technique and kinda report it when they notice it ?
[/quote]

have heard that they can be refused but this requires the person on the till to be very aware of processes and follows them strictly.
The rule for dhl express at least is black only. Probably the same for other carriers, I believe that @mothered did mention that carriers only accept black ink.

The producer of the purple ink, might be able to produce such ink but consciously decided to not make it, due to the possibility for fraud.
As @mothered said, they can still work which package it is even if the ink has disappeared.