How Does Exposure To Moisture Increase An Ink's Apparent Water Resistance?

[A Smug Dill]

Which ink do you think did this on a Rhodia Dotpad No.16 (with 80g/m² paper)?

 

 

 

 

 

 

 

 

 

I really don't understand the chemistry of how this works:

 

 

 

 

 

 

 

 

 

 

(The auto white balance / colour correction in GIMP didn't seem to handle the photos from the bucket list too well, sorry.)

[AmandaW]

Perhaps floating encouraged the ink to soak into the paper rather than simply washing off? It's interesting behaviour, whatever the cause.

[Astronymus]

Same effect as with aquarelle, I guess. Likely not a big discovery. Sorry.

[Tasmith]

Very interesting.

[Eclipse157]

Very interesting indeed, thank you for sharing. My idea is similar to AmandaW's. Soaking only one side of the leaf (I assume the paper was wet only on one side and the upper side was in contact with air) prolly "sucked" the ink deeper into the cellulose fibers, while soaking frm both sides also allowed the dye to simply go away.

[A Smug Dill]

My conjecture:

I suspect there is some sort of coating on both sides of the Rhodia Dotpad No.16 paper that would dissolve upon prolonged contact with water. When the sheet is floating on the water surface, the coating on the verso side gradually dissolves (down) into the body of water, and moisture is then absorbed by the now exposed fibres, causing some chromatographic separation of the dyes on the page. However, the moisture in the fibres below also cause the coating on the recto side to slowly dissolve, but it has nowhere to go except down, and somehow acts as a fixer (to various degrees of effectiveness) on the dyes.

In both instances, after I lifted the floating sheet from the water, allowed most of the water clinging to the sheet to drip off, and then dried the sheet with a paper towel on both sides, no colour came off the recto side — or the verso side, for that matter — to stain the paper towel. Given the long soak has removed all the teal from Noodler's Aircorp Blue Black on the half of the sheet that wasn't floated, leaving only very clear and legible grey marks, I'd expect the same to happen to the other half, considering all the brown dye in Pelikan Edelstein Smoky Quartz bled out of the floated half after a long soak. That the teal colour is still quite vivid on the floated half suggests that the dye got preserved somehow, in a way that the brown didn't.

 

Not shown is the verso side of the floated sheet after the long soak; but all the teal had washed away clean. Given that blurry outlines of writing in teal — matching the haloes on the recto side, I suppose? — could be seen on the verso side after floating (but before soaking), yes, the moisture helped some teal dye get "sucked" into the fibres, but that can also dissolve away instead of forming a permanent bond with the cellulose.

[Astronymus]

Paper is often coated. For example to smoothen the surface or to regulate the ink absorption.