Flattening and preserving old blueprints?

[TimNJ]

Greetings,

Yesterday I bought a 100 year old+ blueprint of a train tunnel in New York. Well, at least a small part of it. See attached.

It looks to be in pretty good condition. I'd like to frame it and hang it up as a decorative piece, so I need to figure out a way to make it lay flat without ruining it in the process. I also want to prevent it from deteriorating further once it's hung up and exposed to sunlight on a daily basis.

Based on a few Google searches, the only recommendation I've really seen was to use a clothing iron set on very low heat. Seems reasonable. No steam I presume? In terms of preservation, UV glass seems like the obvious answer, just not sure if it's effective enough. What is the sensitivity of cyanotype paper to UV after it's been developed? It's clear that this blueprint has faded over time.

Seems pretty niche, but does anyone have any experience with dealing with old blueprints like this?

Thanks,
Tim

[jonpaul]

get AR glass/plastic sheet

Place blueprint  on white flat like foam core
Cover with glass
setup lights 45 deg off axis

take hi res images
use PS to clean up

get 100% size print.

The BPs will all fade unevenly with age

J

[TimNJ]

Thanks. Probably makes sense to not hang the original I guess. Although, I like the historical factor and analog goodness of the original. I also wondered about using some sort of gesso or varnish product directly on the original print (after scanning it of course!). https://www.liquitex.com/us/products/professional/gessoes-mediums-varnishes/matte-varnish-spray/. Perhaps one layer of this and then UV glass in front of it.

Anyway, found this guide with some more details on scanning large documents: https://veteranscurationprogram.org/wp-content/uploads/2017/09/CompressedDigitizing-Oversized-Documents-Operational-Guide_Final-Draft_2013.pdf

Have a 1:1 macro lens and a good camera. I guess it shouldn't be too hard. How about a preferred printing process? I've seen some mention of 'UV ink'.

[jonpaul]

Have 1970..1975 blueprints of Sequerra Tuner schematics and cables (VERY RARE!) and my 1973 Popular Electronucs Super Audio Sweeper.

All folded and fading.

1/ 2005, Took   C , D blue prints to a Fed Ex print  shop, in Manhattan they made a professional scan and printed in B&W at high res full sized cost perhaps $ .100 for 10

2/ Just did the  11x17"  sized PE sch, pencil on velum org (lost) blueprint, tacked on wall, setup studio lights.

RAW images at 12..80 MP.

Used PS CS 6 to remove fading and improve contrast.

We print 12x18 glossy in house, but many online /Costco photo sites can make low cost 20x30 or larger prints.

Alt scan or photo clean up, take to any print house (Staples) they will print any size.

YES for display either mount blueprint in frame with spécial (expensive) UV blocking museum grade glass/plastic OR make copies.

Jon

[SeanB]

Lucky for me the blueprints i have are old, but they are not done with cyanotype, but are an actual litho block print, of India ink on paper, now well yellowed, but still legible. I used an A3 copier to take the individual pages and make copies, so that I had working copies of them that I could draw on while working, to do the few changes needed to them, like adding in replacement relays, and changing out Diazed fuses (a curse of an item to get, as they are not popular here) for miniature circuit breakers.

[TimNJ]

Thanks. I guess I'll need to get big piece of plexiglass to frame this thing anyway, so once I have that, I can use it to flatten it out and "scan" it with my camera.

Kind of funny how damaging UV can be to many different things both natural and man-made, just a few hundred nm difference in wavelength compared to (relatively) safe visible light. Seems like <10% of sunlight is UV. Somethin somethin, Planck's Constant, something somethin.



Is visible light generally not damaging to artwork, prints, etc.? I imagine it could depend a lot on material of course.

Thanks.

[jonpaul]

All light causes fading, proportional to the flux, depends on spectrum (worse for blue/UV ABC)  but varies with the dye etc.

Old ammonia slat DiAzo blueprints fade with light and exposure to air, often unevenly.

Museum displays for graphics, posters painting are in subdued light away from windows and daylight.

The lamps are specifically chosen for low color T eg 3000 K or incandescent color.

The plastic mfg like Rohm, make special museum grade archival plastic sheet to cut the most damaging UV but permit good color rendering.

We us 3..6 mm sheets of matte finish AR plastic, avail in 4 x 8 ' sheets

 OP3 acrylic
https://www.acrylite.co/products/our-brands/acrylite-gallery/uv-filtering
 
Image is the 11 x 17" 1973 Popular Electronics hand drawn schematic blueprint.


Jon

[TimNJ]

Necro'ing my own post.

Anyone have a recommendation for what printing process/materials would probably yield the best results? And/or do you have any recommendations for an online printing service which you like?

Due to thin lines involved, I want it to be as crisp as possible, and no blotchi-ness/un-eveness in the blue. (I guess that might be more of a paper issue.)

When I was looking (back in March), saw some mention of UV printing and other exotic sounding things. Stop worrying and just send it?

If you are interested in this blueprint for yourself, there is a high resolution version here.

Thanks.