Understanding the state of decay of GA paper pulp

[tb]

This could qualify as the geekist thread ever and will probably not be of

interest to many, but I thought I'd share some preliminary experiments I

did earlier this week. In many of my 1930s books, there is a gradient of

yellowing extending from the edges towards the center of each page. I've

been curious about this phenomenon - whether it might be a fingerprint

that - if analyzed mathematically - could reveal the storage conditions

throughout the history of the book. Also, I've been thinking about more

precise ways to quantify paper decay numerically than those used in

comics collecting to date.

 

Here's what I tried:

 

1. Take a scan of a page from a 1936 book in bad shape:

 

 

2. In Photoshop, create a mask of inked areas and remove these:

 

 

3. Generate a grey-scale image that shows gradient clearly:

 

 

4. Compute a 3d surface based on the image generated in 3):

 

 

Side view:

 

 

5. Compute cross section of surface from 4:

 

 

6. Analyze sections computed in 5):

 

 

I haven't had time to do any analysis of the sections so far

and it'll probably be a while before I can do so. However, I

do suspect that the color variations can be modeled with a

relatively simple formula. If this works, it might, for example,

be possible to tell from the gradients that a book was stored

in a hot and humid climate for 30 years and subsequently

moved to a more protective environment.I think there is a

growing need to answer such questions to understand how

fresh/brittle GA books are when determining their value.

This specific technique is obviously much too cumbersome

to be practical for that - I am just trying to understand the

decay process better.

 

Anyway, just thought I'd share my thoughts on this and

hear if other people have thought about scientific ways to

quantify paper quality?

[FFB]

Anyway, just thought I'd share my thoughts on this and

hear if other people have thought about scientific ways to

quantify paper quality?

 

Jesus Christ, and here I always thought that I was doing the scientific thing by holding up my Overstreet OWL card next to a book!

 

This is fascinating stuff. Great thread idea and very interesting analysis.

[Aces]

Anyway, just thought I'd share my thoughts on this and

hear if other people have thought about scientific ways to

quantify paper quality?

 

Jesus Christ, and here I always thought that I was doing the scientific thing by holding up my Overstreet OWL card next to a book!

 

This is fascinating stuff. Great thread idea and very interesting analysis.

 

 

 

Wow...

[Aman619]

I love seeing how the computer can make interesting pictures out of data.... but I just dont see this approach yielding the results you seek. Old fashioned paper chemical analysis would seem to be the way to examine decay, and especially the causes of it since the chemical composition today would reflect what the paper has reacted to over the years.

 

At least you might have to do BOTH analyses. Your imaged approach might identify certain graphic patterns of decay that could be correlated to water, heat, etc. But w/o the chemical analysis, youd only identify different patterns w/o know the causes of each pattern. right?

 

but wow, ANY information gleaned from your work will be useful!

[tb]

Aman,

 

Yes, chemical analysis would be much more accurate. I just did this

as a fun little project (already had the software) to try to see how far

you can get with a simple scan. By coincidence, I happen to have a

large number of MM Mags right now. I'd like to try to compare their

paper quality and try to learn more about how to evaluate it.

 

I do think the scans can tell something about the storage conditions.

Below is a page I tore out of an old phone book. The three outer

edges appear to have aged quite differently.

 

 

False colors:

 

[Aman619]

looks like this phone book was stored on a bokkshelf standing up!

[shiverbones]

wow, hkp thats an interesting area to explorte, very impressive & commendable!

[FFB]

I love seeing how the computer can make interesting pictures out of data.... but I just dont see this approach yielding the results you seek. Old fashioned paper chemical analysis would seem to be the way to examine decay, and especially the causes of it since the chemical composition today would reflect what the paper has reacted to over the years.

 

At least you might have to do BOTH analyses. Your imaged approach might identify certain graphic patterns of decay that could be correlated to water, heat, etc. But w/o the chemical analysis, youd only identify different patterns w/o know the causes of each pattern. right?

 

but wow, ANY information gleaned from your work will be useful!

 

What I like about the charts is that when a book comes back with "Cream to Off-White Pages," it's pretty vague about how far the "cream" parts extend into the book. Hkp's charts show in a three-dimensional way the degree of the toning. Whether or not it's practical for current use, it's a cool idea.

[CentaurMan]

I desperately want to contribute something to this thread, as I acknowledge the work that's gone into it and care about the subject, but I'm totally lost.

 

Hopefully someone else who understands the results you've gotten from the 3-D imaging will chime in and I can enjoy watching the discussion unfold.

[tb]

Actually, the pics were only meant to give an idea of what

I'd like to do. I don't have any results yet. The nice thing about

the 42 MM Mags that I won at Mastronet is that is an original

owner collection. I'd like to do an analysis of these and compare

to the several other original owner and file copy sets that I have.

Hopefully, this will lead to some statistical diagrams where the

data for the different groups will cluster together.

 

Maybe something will come out of it, maybe not. If it does work,

it should be possible to do the same for Larson and other comics

pedigrees.

[kryptonitecomics]

Anyway, just thought I'd share my thoughts on this and

hear if other people have thought about scientific ways to

quantify paper quality?

 

Jesus Christ, and here I always thought that I was doing the scientific thing by holding up my Overstreet OWL card next to a book!

 

This is fascinating stuff. Great thread idea and very interesting analysis.

 

 

That could be the funniest line I have read all year, probably becuase I agree. That's not a knock against the data....it's fantastic, but I also don't know what to make of it.

 

I am still trying to duplicate your charts with my etch-a-sketch