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Scanning old drawings

seajord5

Hi, I have a bunch of old drawings (70+ years) that are in pretty ragged condition. I don't really want to run them through a wide-format scanner. Does anyone have a good phone app they use to scan 24x36 sheets, that flattens the image (removes distortion at the edges)? Or any other technique they use to digitize super old drawings?

Thanks.

 
Dec 4, 22 4:41 pm

Photographing is the somewhat troublesome because optical distortion. If its actual blueprint, the scanner won't necessarily harm it. If it is original master drawings on tracing paper and such, what I would suggest you do is to make a light exposure box for UV and use UV-A LED strips and acrylic sheet. Get some diazo paper and some ammonia... highest concentration levels that you reasonably get.... around 10%. Diazo machines usually used 30% concentration level but it doesn't need to be that high.... it just makes the diazo process take a little longer. UV exposure from UV-A LEDs should be relatively short especially if the paper is only about 2 to 3 inches from the LEDs. You will need to do some test runs but it should only but it's contact photography. Once you do the UV exposure step, use a spray bottle to spray onto the 'exposed' sheets that had the diazo emulsion. Once you got a decent copy of each sheet, then you can run those through regular wide format scanners. If you could find a large enough-size Flatbed scanner then you can skip the who diazo copy steps. What I am suggesting avoids lens distortion that can cause you a lot of hassle finessing it so it isn't all funky. Otherwise, you'll have to redraw the drawing by hand or in CAD. Cameras can distort the drawing and kind of warp it. There are tools that can somewhat clean that up but it still have just enough pesky distortions that can be annoying. 

The above to much a pain????

You can potentially use professional reprographics services experienced with handling old historic drawings.

Dec 4, 22 5:41 pm  · 
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seajord5

Thank you for the feedback! I have to look up the diazo process ... I am not too familiar with the chemical process for creating blueprints. Actually the blueprints I have are in fine shape, but the newer paper prints I have from the early 60's are torn and crumbling on the edges. They belong to the client so I do not want to tape them to a piece of paper in order to run them through a wide format scanner, which I have done, but sometimes the machine also "eats" the print. Ideally, I think the best would be to find a flat-bed scanner that can do a 24x36 like you said. I haven't been able to find one, but maybe they exist. If not, I think I will have to just read the dimensions off of the sheet and re-draw in Revit, which is what I need to do anyways. It is just convenient to trace over the original first, then clean up dimensions by reading right off of the screen. Thanks again.

Dec 4, 22 6:37 pm  · 
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There is two types of 'blueprint' process before modern xerox, inkjet, laserjet printing. The two processes are cyanotype and diazotype. The one above is likely diazo process if it isn't an original pen/paper but the blue hue on the parts of the drawing title block near the bottom lends to it being diazo. However, the original architects/designer/whatever seemed to have used a fairly light weight diazopaper where newer diazopaper that has the diazo emulsion coating is a little heavier weight more like solid bond paper. Cyanotype is the process used in the 1956 blueprints below. The blueprint itself is a copy using paper that was more like watercolor paper in weight and is coated (pre-coated or manually coated by the architect/designer/whoever working on making the copy) with a different emulsion. Cyanotype used this heavier paper because the cycle after UV exposure (sunlight but UV-A spectrum is key for the emulsions used in cyanotype and also diazotype) cycle is the development cycle. In cyanotype, it is referred to as a wet process where the paper in submerged in water. One pan of water of just water and one that may have a cap full of hydrogen peroxide. Then let to dry. The diazotype process (diazo for short) used ammonia instead and was considered 'dry' or 'moist' but not wet as the ammonia is used as the 'developer'. This is akin and should seem familiar to classic film photography and share similar principles. NOTE: Neither cyanotype or diazo process needs a really dark room for the post UV development cycle. It needs to not be in direct sunlight through any windows. It's more forgiving than film photography. These processes, you will want to control the process and do some tests to get the timing right on UV exposure stage. Making a large format "light box" with UV LEDs, where gloves, some opaque clothing, protective eyewear for UV, and minimize direct exposure of your skin to the UV. UV-A spectrum will usually not result in any issues but it's just operational safeguard and general safe practice. Diazo process requires use of ammonia and you will want ventilation for that. Cyanotype will typically be safer.

Dec 5, 22 12:39 am  · 
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seajord5

Thanks for the helpful info on this process - very interesting to learn how things were done before CAD and plotting

Dec 8, 22 9:31 pm  · 
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seajord5

Here are the blueprints from 1956 in great condition

Dec 4, 22 6:40 pm  · 
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atelier nobody

I've sent a LOT of old drawings for scanning and never had a problem with them getting damaged.

Dec 4, 22 11:41 pm  · 
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Blueprints will typically feed fine through the rollers of the wide format scanners. 

Seajord5, if it is a color scanner, that may actually be good because a black & white scanner will typically result in the blue being black and results being such with more to be desired. Blueprints like that are cyanotype process (traditional BLUEPRINT). It might be possible to make a positive by using the blueprint as the original to make a copy from but in that case, it would become a positive. However, the 'white lines' needs to be high contrast, sharp, and clean. Your copy is kind of not as good for doing that because there is a good chance come of the lines and such won't come across. I would not use the photo above. I would try to process as clean and orthographic photo with the sheets firmly flat. Otherwise, it would be too much headache. In such case, I would practically redraw it in CAD using the measurements given and extrapolate the rest.

Dec 5, 22 12:17 am  · 
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Professional reprographics services by those who routinely work with historic blueprints will usually be setup with staff that are competent with handling such and would have the equipment to scan such documents. If I was going to prepare the diazo copy for scanning, if there is nothing on the back side, I might use some tacky clue to bond it to a sheet of bond paper with all the edges adhered flat so it can go through scanners easier.

It is a delicate work in some cases but it is something that is sometime done.

Dec 5, 22 12:45 am  · 
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bennyc

I use the app Turboscan for scanning drawings and prints, works pretty good, gives you options to adjust exposure, color etc

Dec 7, 22 5:02 pm  · 
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Almosthip

When I have to scan large format drawings with ripped edges I cover the edges with packing tape so that they dont catch in the scanner.  I will tape both sides of the drawings.  I do this LOTS and never have issues


Dec 7, 22 6:40 pm  · 
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That would work. Sometimes you may run into issues but not so much with the scanner device but with whoever the plans belong to. If it belongs to a historical society or similar organization, they may have more stringent standards.

Dec 7, 22 7:25 pm  · 
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seajord5

Yes, I have taped sheets before, but since these belong to the owner, I'd like to avoid going that route. I saw on youtube there is a guy who mounts blueprints to heavier posterboard with a roll-on liquid adhesive - if I had more time and the owner wanted to pay for i would consider doing something like this guy Posterfix on youtube-


Dec 8, 22 9:28 pm  · 
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posterboard would be too heavy stock for scanning. Same approach can be applied to a single sheet of bond paper. Basically, the adhesive is rubber cement and can be rolled on, brushed on, or sprayed on. It would be something carefully done. Does the back side of the sheet have anything that may be of historic significance? Some sheets may feed through just fine but a sheet that had some damaged edges in fragile condition requires delicate handling and conversation with the owners of those copies of the plans. I've heard of linen backing restoration techniques. The linen backing should be starched and also have sizing used to give it a more paper like characteristic.... much like our dollar bills in order to feed properly through any scanner.

Dec 8, 22 10:00 pm  · 
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Almosthip

I've never had issues with the owners being upset at the taped drawings, as I give them all the scanned files on a flash drive. They are usually happy they don't have to bother with the hard copies anymore.

Dec 9, 22 11:15 am  · 
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Almosthip

We digitized all my local school boards drawings for them, and manage the files. If they need a drawing of their schools they call me. And then when they need permit drawings for a renovations, they also call me/ us.

Dec 9, 22 11:18 am  · 
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seajord5

Ultimately I ended up just taking photos as flat as I can, imported to Revit, scaled, read the dimensions off of the sheet and just re-modeled/drafted in Revit...

Dec 8, 22 9:34 pm  · 
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masonk

Learning like yourself @Seajord5.  A lot of Universities, Libraries or Art galleries scan large-format images using a planetary scanner and some Universities even seem to have a low volume pay-as-you-go/use option.  You can use AO+ flatbed scanners too.  Search for those using Quartz i2S, or Cruze scanners; these are planetary scanners used on digital preservation projects.  Others, like SMA Versacan 36100 are A0+ flatbed scanners and yes they exist and small companies have them for such needs as yours.

As Richard Balkins mentions, depends on the standards required, and the importance to you (or historical importance) of the originals.  

The University of Illinois has some useful data to refer to.

Architectural Drawing Reproduction

https://psap.library.illinois....

Architectural/Technical Drawing Reproduction: Support Materials  

https://psap.library.illinois....

Also, I could suggest two books, but hard to get books, that have some useful background information advice on storage of prints to help avoid damage etc.

"Administration of Photographic Collections", SAA Basic Manual Series 1984.

"Photographs of the Past, Process and Preservation", Bertrand Lavedrine, 2009.

I should credit my wife for having all this handy, as I'm not that clever or well versed in the subject.  Especially the books, as these were part of her MSc in digital archives and preservation.

Dec 9, 22 5:32 pm  · 
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seajord5

Wow very interesting info - thank you! Reading through the web links now.

Dec 9, 22 7:11 pm  · 
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