Scanning and emailing A3 artwork

[Spaceghost]

Hey all. Sorry if this has been covered elsewhere in the forum. I had a quick look but can't see anything.

Does anyone have any advice about the best way to scan A3 art using an A4 scanner? Also, what's the best resolution to scan black and white (or graytoned) inked artwork for emailing purposes?
I'm currently scanning the top and bottom halves seperately at 300 DPI and sending 2 different files. Is it possible to re-attach the 2 halves before I send them? If so, how?

Apologies for being thick at computers but with your help, I'll learn.

[Spaceghost]

...oh yes, also, what's the best file type to use? BMP? JPEG? Whaaaaat?

[Jim_Campbell]

Hey all. Sorry if this has been covered elsewhere in the forum. I had a quick look but can't see anything.
Apologies for being thick at computers but with your help, I'll learn.

This tutorial covers stitching artwork scanned in parts back together in a manner fairly close to the way I used to do it:

http://misskittyoooo.deviantart.com/art/Scanning-Large-images-66872892

Optimum resolution depends on the intended purpose of the artwork. Actual size at 300dpi is overkill unless it's being used for print. If it's intended for web use, leave it big and knock the resolution down to 96 or 72dpi and send a JPEG. If it's print, leave it as it is and send it as a TIFF with LZW compression. If it's lineart to be coloured, you can reduce the filesize still further by using the Threshold function in Photoshop to drop out all the fuzzy grey edges and leave hard B&W lines. Change the Mode to Bitmap and save as a TIFF with LZW and the file will come in at a few hundred Kb.

If you have files that are a bit too big to e-mail (there's a 20Mb cap on attachments on my account, f'r instance) then either use a service like yousendit.com whose free option allows you to send files of up to 100Mb, or sticking the files up on any free webspace your ISP might have provided will work as an alternative.

Cheers!

Jim

[radiator]

Never use JPEG - it compresses your artwork and you'll lose quality. Use PSD for working files (if you are using Photoshop), and use TIFF format for flat files.

Before I got my a3 scanner, I would scan artwork in three sections - D'Israeli has a good tutorial about this here: http://homepage.ntlworld.com/lynnfo/educatio/scanning/scannn02.html

I always scan in colour, then convert the file to grayscale in photoshop after I've scanned - in my experience most scanners preset 'black and white' or 'linework' scanning modes suck - don't use them. Scan at 400dpi, then scale the file down to 300 dpi once you have it in photoshop.

For sending, zip the file(s), sending them via YouSendIt if need be - generally grayscale files are tiny though.

[Dandontdare]

Actual size at 300dpi is overkill unless it's being used for print. If it's intended for web use, leave it big and knock the resolution down to 96 or 72dpi and send a JPEG. If it's print, leave it as it is and send it as a TIFF with LZW compression. If it's lineart to be coloured, you can reduce the filesize still further by using the Threshold function in Photoshop to drop out all the fuzzy grey edges and leave hard B&W lines. Change the Mode to Bitmap and save as a TIFF with LZW and the file will come in at a few hundred Kb.

This makes me cry as it shows up just how ignorant I am. It's all greek to me!

[Spaceghost]

Heh, it's fairly Greek to me too.

Thanks a lot for the comprehensive responses Jim and Radiator. I'll have to do some homework on this I reckon.

[Trout]

Wow. I've done a few basic courses at work recently - mainly out of fear of the future - and am astonished to discover I understood some of this thread.

Usually the only Jim Campbell statements I understand are "Don't use a crossbar I" and "Fuck off, you cunt, or I'll destroy your entire life."

- Trout

[Jim_Campbell]

Heh. I've been meaning to put together a beginners' guide to resolution, colour depths and file formats, since getting hand draw artwork into your computer in the best possible condition can be deceptively tricky, but I just haven't had the time.

OTOH, if anyone wants to post any questions here, or in another thread, or wants me to expand upon or clarify anything I've said upthread, please say so and I'll make the time. There aren't actually many areas where I'll put forward my opinion as actually being expert, but I've scanned more images than anyone on this board has had hot dinners, so I do actually know what I'm talking about...

Cheers!

Jim

[Dog Deever]

Dammit- only just saw this- I kind of knew most of it except for where to find the 'threshold' function in photoshop. I'm using Photoshop 7 (yes it's old, but I don't have squillions to spend on Adobe products. If it's not available on that version, I have access to CS 3 at work, less handy but it could be done.
Now Jim has gone, driven away by far less helpful, knowledgeable and useful idiots.
I his absence, anyone know anything about this Threshold thing of which he speaks?

[radiator]

Go to the top bar and choose Image>Adjustments>Threshold and use the slidey bar to apply it - it's definitely present in PS7.

Personally I never use it, preferring to use a Levels adjustment layer, or several, to boost the inks and whites. Threshold is pretty harsh (like using a sledgehammer to crack walnuts imho!) and will tear your inks to shreds - as will converting the image to bitmap. Apparently this is common practice, but I find it a bit odd that someone would spend so long on delicate brush and pen work only to destroy all the subtlety in PS. Perhaps it was a necessity in the days of slower computers (to keep file size to a minimum), but these days I like to retain as much detail as possible.

Do a Google search on adjustments layers, or you can apply levels directly to the current layer by hitting Cntrl+L (or Option+L on a Mac) - OR going Image>Adjustments>Levels.

Hope that helps!

[uncle fester]

Levels are your friend, kids. Radiator speaks the truth

[CrazyFoxMachine]

Yep - I just scan in the page in more bits than is necessary and slot them together. USING DIGITAL WIZARDS

[radiator]

To illustrate what I mean:

Here is the original scan of some lovely inks by Gibson Quarter:


Here is what happens when you apply Threshold (converting the image to bitmap has the same result):


And here are the same inks cleaned up using two Levels adjustment layers. Additionally, layer masks allow for total control - enabling you to apply the adjustment to specific parts of the image:

[Spaceghost]

Riiiight. That really does make a difference. Would you be able to do that with grayscale inks too or would that process mess up the tones?

[radiator]

Yes, you can use levels on gray tones to punch them up a bit (almost everything you scan will need to be corrected in some way - scans tend to look a little washed out, and can always do with a little added contrast). Levels are applied with a slider, so you can add as much or little as you like - just do whatever you think looks good.

To use levels in this way, you need to drag the black and white handles towards the centre (on the top slider - 'Input Levels'):