Dry Time Paradox - calling all scientists!

[LizEF]

Anyone who has followed by Extra Fine Nib Ink Reviews will know that I often record dry times at over 2 minutes (I refer to this as "eternity").  Given that I'm using a Japanese EF nib and that I live in an arid climate, this just seems wrong.  I've spent some time pondering it, though and have a theory.  I would appreciate input from anyone, especially our resident scientists.

 

Analogy: Have you ever noticed that a damp rag will absorb spills faster than a dry rag?  This is basically my theory: High(er) humidity "compromises" the sizing (at least on Rhodia dot pads, if not generally), so that paper that "lives" in areas of higher humidity will absorb some of the ink, leading to faster dry times, despite (presumably) slower evaporation times.  (I suspect absorption happens faster than evaporation, regardless.)  In my arid climate, the sizing of the dot pad is as intact as it can be, making the paper, though dry, slow to absorb any of the moisture.  Therefore, drying happens (almost?) entirely by evaporation, and even though evaporation is fast here in the desert, it's not as fast as absorption elsewhere.

 

We know from other reports that moisture can "ruin" paper.  I have to assume that Rhodia dot pads aren't completely ruined by ordinary humidity - otherwise we'd be reading a multitude of reports about bleed-through, spreading, and feathering.  But perhaps it has enough of an impact on the paper to affect dry time?  And perhaps there's some tipping point - too much humidity and the paper is so damp it doesn't take ink, or spreads and feathers like crazy; average humidity and the paper is fine and happens to have faster dry times via a small amount of absorption; too dry and the paper's sizing is basically impenetrable, requiring ink to dry only by evaporation.

 

Thoughts?

[yazeh]

I'm curious too. In my humid climate I tame wet ink with thick absorbent paper (Peter Pauper Notebooks). 

Rhodia is always the middle ground, it's not a paper I use (only for reviews). 

The longest dry times I've observed on Midori or Tomoe River 68 gr paper, depending what ink, I'm using. 

 

[Sailor Kenshin]

1 hour ago, yazeh said:

I'm curious too. In my humid climate I tame wet ink with thick absorbent paper (Peter Pauper Notebooks). 

Rhodia is always the middle ground, it's not a paper I use (only for reviews). 

The longest dry times I've observed on Midori or Tomoe River 68 gr paper, depending what ink, I'm using. 

 

I may not be all that science-y, but you are right about Midori/Tomoe River dry times.  I always have to be careful with those papers.

 

@LizEF, have you tried the Dry Time thing on any different papers?  Interesting topic, thanks.

[LizEF]

1 hour ago, Sailor Kenshin said:

@LizEF, have you tried the Dry Time thing on any different papers?  Interesting topic, thanks.

I haven't done the dry time test on other papers, no.  I suppose I could start, but I'd probably have to go a couple hundred more inks before drawing conclusions.  I do know that TR always takes longer and the 90gsm ivory vellum Clairefontaine paper in my Rhodia Webnotebook that I use as a journal is more absorbent and the ink dries faster.  And inks dry almost instantly on the two absorbent papers I use for reviews.  I guess that would be a good test of my theory, though, start testing dry times on other papers.  Not sure I wanna go to the effort (or "ruin" notebooks to this cause), though...

 

I always use blotting paper for bookmarks, so dry times aren't something I really pay attention to except for my reviews.

 

I shall ponder.

[Bo Bo Olson]

I don't do time tests....outside of Noodler's Golden Brown, which is a full sheet of the next paper until the front of the first is dry enough to write on the back.

Much of the time I find F to be skinny enough, but I often hung around in B or BB nibs. I now like an M.

I have an EEF old vintage no name Euro pen that needs a new gasket.

 

Sometimes when lately when I edit, I find EF (semi-flex  (euro) to be a tad wide....but there I'm not looking for shading ink....just a tiny line. A long  wander from vintage stubbed semi-flex B and BB

[lapis]

5 hours ago, LizEF said:

Analogy: Have you ever noticed that a damp rag will absorb spills faster than a dry rag?

 

Right on! I am/was a scientist but your analogy above says it all. The best "verification" IMO is just the use of more vocabulary concerning the same game... Co hesion versus Ad hesion.

[LizEF]

28 minutes ago, lapis said:

Right on! I am/was a scientist but your analogy above says it all. The best "verification" IMO is just the use of more vocabulary concerning the same game... Co hesion versus Ad hesion.

Thank you, @lapis!  So many things about this hobby end up being counter-intuitive - ink dries slower in arid environments (though it evaporates more quickly from poorly sealed pens).  Dry inks look wet.  Wet inks dry faster (due to spread and soaking in).  No wonder the rest of the world think we're nuts!

[BrassRatt]

on Science -- 

There is an experiment you could do to test your theory, or at least to verify that more humid environment leads to shorter dry time with your particular paper: 

 

1. prepare a small  chamber (a box or similar) with controlled humidity inside.  Cigar folks do this in "humidors" and there are gadgets that release/absorb water vapor to keep a steady humidity.  

2. place a sheet (or a few) of your test paper in the box for several hours or overnight.

3. do the dry-time tests on the humidified sheet and on a regular arid-climate sheet to compare results. 

 

As a quick-and-sloppy humidistat, cookie-bakers sometimes use a cut-up apple in the cookie jar.  But I don't know the RH that results. 

 

Fun?

 

 

[amberleadavis]

@InesF and @dipper have done some great work explaining the chemistry of ink so I'm looping them in to this thread.

 

@LizEF I have an old (beyond vintage) cartridge of Sheaffer Skrip Black that did not dry after 3 years.  I'm pretty sure the answer is chemistry. 

 

[InesF]

1 hour ago, amberleadavis said:

@InesF and @dipper have done some great work explaining the chemistry of ink so I'm looping them in to this thread.

Thank you @amberleadavis for your trust in science!

 

There are two things not to mismatch:

- liquid (light reflecting) ink is disappearing from the surface of the paper, mostly due to capillary action

and

- ink contents are evaporating (remember: water is not the only liquid in well composed inks)

 

If ink is only sucked into the paper, it may look like dried but you may still smudge it with your finger or with a rubber eraser or such.

If ink contents are evaporated, usually, a solid dye remains on top of and in between paper fibres.

 

Surface hydrophobisation is a well known phenomenon of organic matrices, such as humus, peat, charcoal etc. As long as those materials are slightly damp, more water is able to enter capillaries and the material appears to be hydrophilic. In case all water is evaporated (heavy sunshine, drying oven, ...) the surface gains hydrophobic properties and water droplets are rolling off from the surface. In a plant pot, a water layer may sit there for an extended while. During that time, water vapour is slowly entering the material, making it hydrophobic again and then, all of a sudden, all the water is sucked in the soil matrix within seconds.

 

As seizing of paper is typically a production secret, chances are good that such behaviour may appear also with paper. Purified cellulose is hydrophilic and will always adsorb and absorb water. Even in an arid environment with, lets say 20% air humidity, water will be associated at the cellulose fibre surfaces making som weight percents of the cellulose. In case incompletely purified cellulose is used for paper production, such a material still containing a significant amount of lignin (not wood-free paper types), may also have this surface hydrophobicity after (almost) complete drying.

 

Has the ink fully dried when all water is evaporated? What about components, such as glycerine or ethylene glycol, which will evaporate during the next week (or so)?

 

Keeping in mind the two different types of "drying appearance" of freshly applied ink, we should consider that the processes can get complex and counter intuitive.

Being real world persons and keeping in mind that the result is more important than the "drying" process, I vote for staying intuitive and calling it drying.

As well informed and educated fountain pen users, we enjoy the drawing of wet ink lines on paper, have fun in watching how it dries and getting joy out of the fact that we are doing complex science with each line.  👩‍🎓

 

 

Edit / PS: Here is a nice read about how to adjust hydrophobicity of cellulose: https://doi.org/10.3390/polym13081241

[LizEF]

9 hours ago, amberleadavis said:

@LizEF I have an old (beyond vintage) cartridge of Sheaffer Skrip Black that did not dry after 3 years.  I'm pretty sure the answer is chemistry. 

Holy cow!  You mean it didn't dry on paper, right?  (Not that the ink in the cartridge remained fresh?)  Chemistry, physics, one of those science-y things smart folk are always talking about. ...

[LizEF]

9 hours ago, BrassRatt said:

on Science -- 

There is an experiment you could do to test your theory, or at least to verify that more humid environment leads to shorter dry time with your particular paper: 

 

1. prepare a small  chamber (a box or similar) with controlled humidity inside.  Cigar folks do this in "humidors" and there are gadgets that release/absorb water vapor to keep a steady humidity.  

2. place a sheet (or a few) of your test paper in the box for several hours or overnight.

3. do the dry-time tests on the humidified sheet and on a regular arid-climate sheet to compare results. 

Excellent idea!

 

9 hours ago, BrassRatt said:

As a quick-and-sloppy humidistat, cookie-bakers sometimes use a cut-up apple in the cookie jar.  But I don't know the RH that results. 

Or, as grandma taught: if you have mints that are supposed to be soft, but have gone hard, put them in a bag with a heel from a loaf of bread - the mints will suck the moisture from the bread.  (I suspect the only reason the heel was specified was because it was less popular for eating than the other slices.)

[LizEF]

10 hours ago, InesF said:

There are two things not to mismatch:

- liquid (light reflecting) ink is disappearing from the surface of the paper, mostly due to capillary action

and

- ink contents are evaporating (remember: water is not the only liquid in well composed inks)

 

If ink is only sucked into the paper, it may look like dried but you may still smudge it with your finger or with a rubber eraser or such.

If ink contents are evaporated, usually, a solid dye remains on top of and in between paper fibres.

...

Your knowledge is helpful and impressive, as always!  My take away is that "dry time" - which we measure by whether the ink still smears when you rub your finger across it, can indeed be impacted by how hydrophobic the paper is, and that paper in an arid climate can indeed cause paper to become hydrophobic (depending on the paper's composition and sizing).

 

I like the idea of conducting @BrassRatt's experiment.  I just have to figure out how to humidify a sheet of paper...

[yazeh]

@InesF thank you so much for your precise explanation, I read it a couple of times 

@LizEFthis is how the rabbit hole of humidors started  You can put in a hard candy  We'll see you doing Efnir's in a humidity controlled room with Klaw smoking a cigar at the controls 

 

 

[LizEF]

32 minutes ago, yazeh said:

@LizEFthis is how the rabbit hole of humidors started  You can put in a hard candy  We'll see you doing Efnir's in a humidity controlled room with Klaw smoking a cigar at the controls 

  Zero chance.  But it does appear that a humidor may be the easiest way to do this - or at least, these packet things that you can put in a sealed container.  On the other hand, I'm also wondering if I can do something as simple as boiling water in the microwave, then stick a sheet of paper on a rack inside and let it suck up the water vapor...   I shall let the back of my brain work on it.  No cigars, though.

[amberleadavis]

On 10/4/2023 at 8:46 AM, LizEF said:

Holy cow!  You mean it didn't dry on paper, right?  (Not that the ink in the cartridge remained fresh?)  Chemistry, physics, one of those science-y things smart folk are always talking about. ...

 

Yes, years later the ink was still sticky on the paper ... but it looked cool.

[Bo Bo Olson]

I wasn't in the States,so never had an urge to buy;  but remember reading hear of some Private Reserve inks that still smeared a year or two or more later....

My slowest was Noodler's Golden Brown. Write a full front page on the next page to come back to write on the back of the first sheet. Which is 'rather quick' to what I'm reading here.

[LizEF]

1 hour ago, amberleadavis said:

Yes, years later the ink was still sticky on the paper ... but it looked cool.

Wow.  Just, wow.

[arcfide]

I think the never-dry effect can happen with some highly saturated inks that have low water content, right? That's what I had surmised at least. 

 

I think if the ink doesn't manage to absorb into the paper, whatever the case, then you are left with whatever can evaporate, and if you've ever done this test with some inks (drying them on a non-porous surface), you'll find that some inks dry very slowly and have some ingredient which doesn't actually dry so much as congeal. With inks that have a higher water content (my guess), the inks will dry down into a very distinct powder or chalky appearance, or sometimes to that sheeny look. I think I noticed this a little when I added White Lightning to some inks. Of course, sometimes that extra surfactant can increase the absorption into the page, so it's an interesting balance, I think. 

[LizEF]

1 hour ago, arcfide said:

I think the never-dry effect can happen with some highly saturated inks that have low water content, right? That's what I had surmised at least. 

Yes, but my issue was that my dry times for some inks are so much longer than other people's for the same inks.  In theory - or at least by intuition - my dry times ought to be faster.

 

1 hour ago, arcfide said:

I think if the ink doesn't manage to absorb into the paper, whatever the case, then you are left with whatever can evaporate, and if you've ever done this test with some inks (drying them on a non-porous surface), you'll find that some inks dry very slowly and have some ingredient which doesn't actually dry so much as congeal. With inks that have a higher water content (my guess), the inks will dry down into a very distinct powder or chalky appearance, or sometimes to that sheeny look. I think I noticed this a little when I added White Lightning to some inks. Of course, sometimes that extra surfactant can increase the absorption into the page, so it's an interesting balance, I think. 

Ah, this presents another possible experiment, but it would require more than one person: testing dry time on non-porous surfaces.  Of course, lots of controls would be required or the results couldn't be compared in meaningful ways, but it could be done, in theory...  Or, one person could do it, but they'd need a way to have identical samples in multiple humidity-control chambers....