How do I resize and make line art smooth when blowing up line art in Photoshop?

[PrintDriver]

There's another problem with line art you are all overlooking and that is the interaction of the ink with the paper. I enlarge old handrawn maps all the time. At some point, and it's not too large, you are going to see the unevenness of the line work, due to the tooth of the paper and the uneven pressure of the inking tool.

The ideal method is the old fashioned method of actually getting the work photographed to color transparency then scanning the transparency in a drum scanner at some obscenely high resolution, at least 2400ppi. This work flow is hard to find. I have one guy left in the Boston area that does it, and the photo shoot can get expensive so best to have a plan of attack and book a full or half day.

Most desktop scanners only scan to 300ppi and interpolate the rest. Even if it says 600, you need to determine if it is a true 600 (optical vs interpolated) and a scanner is only as good as the smaller number of the two given for it's optical resolution. If you are going to take these to the level of what is called true giclée (and that term means a lot of things these days, but more on that in a minute), you want to find a service bureau that can either flatbed scan these or cruze scan them. Though for something this small, the cost of a cruze scan is sorta...overkill. You use a cruze scanner for oversized stuff or for stuff that has a 3D texture to it such as a hand-brushed painting where the lights even out the high points...But anything for fine art eh?

Giclée. I can't tell you how much I hate that term. In the early 90s it was a glorified Iris print. Today, it's any of a number of glorified inkjet print processes, usually aqueous based. If you want them done right today, you have to look for a printer willing to run their machine on grass-grows-faster speed (at least 1200dpi) on archival paper or media with archival UV stable pigmented inks. You need to talk to them first to find out what their optimum resolution is for output. It might surprise you. It could be 200ppi or it could be 400ppi. Rarely 600ppi.

If I were a collector of line art, I'd prefer an etching or a high end litho over anything described as giclée, unless I knew who the printer was.

[sully1251]

< b > On the PMT question: No, I haven't used a PMT since 1988 either but I know a couple of guys back in Ohio who are still able to pull one (or the equivalent) out of a hat when they have to for a friend of mine. As odd as my suggestion may have been—it would work.

Here are a few some random thoughts:
We really should be seeing a sample of the art. I was guessing that there may be textures in the line art (like a dry brush technique) that would be hard to duplicate in Illustrator. If the working size was a little larger than 8.5 x 11 (12 x 18 or 16 x 20 for example) you could probably get a good scan at the enlarged size. Some fine-art line drawings that are loose and with some brush texture are enhanced to a degree when enlarged—paper texture and all.

My watercolors are in the 17 x 28 size range—I have them scanned from the orininal art at actual size, using 300 dpi resolution, by a local digital graphics firm. Scans that size cost me about $50.00. The files wind up at about 135 Mb. I usually have to color correct them to some extent in Photoshop at full size.

PrintDriver: I respect your opinions— especially on production. You mentioned that if you were a collector of art you would prefer an etching or a high-end litho over a giclee. That's a reasonable opinion. However, there are good reasons for reproducing artwork as a giclee—assuming you are producing a true giclee. An Iris is not a giclee. I have most of my watercolors reproduced as giclees. The color from an Epson fine art printer is excellent and is as close to continuous tone as you can get. I can hardly tell some of the prints from the originals. The images are printed on watercolor paper and both the ink and the paper are achival. The ink used is reasonably UV stable. One of the best advantages for the artist is that you do not have to print a high quantity—as few as two or three at a time.

[PrintDriver]

Giclée started with Iris prints. There was a small window of time when Giclée was ONLY Iris prints.

And I would consider something called a Giclée to collect if I knew who printed it.
Considering over the years we've had far too many people on here printing their own stuff on a desktop epson and calling it a Giclée...not to mention professionally hearing of vendors who considered an HP5500 print as Giclée worthy...
I know a few photogs that do limited edition prints on the Epson you are talking about and they do them in house. Nice work. If I could afford them, I'd consider them.
Limited run is an advantage for the artist. Again as a collector, unless I knew the series was limited, no go.

As a side note, I once asked an Epson sales rep about their 200 year ink. He said, "...maybe it would last that long–in a box under your bed."

A PMT...is that a stat camera? Not heard it called that, but I came into the game just as they were phasing out. Good luck on finding one of those. Most everyone I know has tossed their conventional camera equipment. Sad really. And for just the OP's reason. It is really difficult these days to find high quality large format stock imagery, or once found getting it scanned. I dread the day my one vendor tells me his drum scanner goes toes up. They don't plan on replacing it.

[hank_scorpio]

Scan at the highest resolution possible. I wouldn't consider 600 ppi high enough resoultion for line art.

I'd be at a minimum of 1200 ppi just to get it to look as it does at normal size.


The best way to enlarge the size is at the scanning stage.

If you want to go from 8.5 inches to 30 inches

Then scan at 350% and I'd say AT LEAST 1200 ppi. But I'd go for 2400 ppi so I'd have more room to play.


If it's ok at that size - then you can start to bring down the resolution to get a smaller file size.

[hank_scorpio]

That should be 353% (rounded up)

[Bob]

Originally Posted by hank_scorpio

Scan at the highest resolution possible. I wouldn't consider 600 ppi high enough resoultion for line art.

I'd be at a minimum of 1200 ppi just to get it to look as it does at normal size.


The best way to enlarge the size is at the scanning stage.

If you want to go from 8.5 inches to 30 inches

Then scan at 350% and I'd say AT LEAST 1200 ppi. But I'd go for 2400 ppi so I'd have more room to play.


If it's ok at that size - then you can start to bring down the resolution to get a smaller file size.

I hate to disagree with an arachnid (especially one with military powers) but....

The problem with that advice is that many people presume 'highest scanner resolution" to equal highest optical resolution. Which just isn't true. Our mutually respectable trade expert David Blatner suggests a different line scanning method (which I described upthread) in his 'Real World Photoshop' book. It is contrary to what the theory describes, but scanning in highest optical grey, and THEN upsampling 300-400% followed by USB sharpening works way better for capturing lineart quality and detail. In fact, it allows you to get great high rez line scanning results even from a lowly 300 ppi optical scanner.

I think the other real question here is the outputting specs. As PD says, the Giclee designation is very vague these days. If we're talking about a high-rez stochastic dot output, and the line is solid black -- it might be better to go the composite route -- very high rez (1200 dpi say) bw overtop of a 300 dpi colour. But there's a lot of 'ifs' in that call.

[garricks]

Originally Posted by Bob

Our mutually respectable trade expert David Blatner suggests a different line scanning method (which I described upthread) in his 'Real World Photoshop' book. It is contrary to what the theory describes, but scanning in highest optical grey, and THEN upsampling 300-400% followed by USB sharpening works way better for capturing lineart quality and detail. In fact, it allows you to get great high rez line scanning results even from a lowly 300 ppi optical scanner.

I happened to have the opportunity to use this method shortly after the last time you posted it Bob, it worked beautifully. Thanks again for posting.

[hank_scorpio]

Originally Posted by Bob

I hate to disagree with an arachnid (especially one with military powers) but....

The problem with that advice is that many people presume 'highest scanner resolution" to equal highest optical resolution. Which just isn't true. Our mutually respectable trade expert David Blatner suggests a different line scanning method (which I described upthread) in his 'Real World Photoshop' book. It is contrary to what the theory describes, but scanning in highest optical grey, and THEN upsampling 300-400% followed by USB sharpening works way better for capturing lineart quality and detail. In fact, it allows you to get great high rez line scanning results even from a lowly 300 ppi optical scanner.

I think the other real question here is the outputting specs. As PD says, the Giclee designation is very vague these days. If we're talking about a high-rez stochastic dot output, and the line is solid black -- it might be better to go the composite route -- very high rez (1200 dpi say) bw overtop of a 300 dpi colour. But there's a lot of 'ifs' in that call.

I've only ever worked with industrial drum scanners. I don't think I've ever used a flatbed scanner for scanning line art.

Results of a desktop scanner are not really something I'm accustomed to.


I've always scanned the image to the size and resolution that I intend to use. It would be a mortal sin for me to alter the resolution, rotation, or even the colour mode after I've scanned an image.


If the Blatner has a better way of Scanning line art then great. I've never done it that way. But if it gets good results, then that's all that matters.

[hank_scorpio]

Just read the chapter in Real World Photoshop on scanning. Bascially the same idea, except I skipped some things.

What I was saying was to scan at a the scanners highest resolution, and at the target size.

The other way described in the book is to scan it twice the size you need and scale it to 50% to double the resolution.

Which is basically the same as scanning at your target size and the same ppi.


The bit on the scanning in grayscale and using the 8 bit information is very clever. I've worked with some people who scanned for a living, and I've never seen that trick before.

It's clever.


But he does note on page 680 - "Note that if your scanning software can interpoplate up to this same resolution, you can us that as you scan and save yourself a step".


Pages 678 - 681, I've scanned like that the way it's described for years.

[PrintDriver]

The Epson dual lens Perfection has an optical resolution of 4800dpi. Even a consumer style Canon can have an optical resolution of 2400.
The old industrial scanners (Creo, Lanovia, etc) all seem to have bit the dust. Scanning is becoming a thing of the past believe it or not. Finding a production quality flatbed scanner with a bed larger than 8.5 x 11 ish is very very difficult.

Depending on the Cruze scanner, you can get as high as 10000dpi or more depending on the lens system, but some of them are fixed at 300 optical/600 interpolated (the smaller static light table models).

Broacher I have a map project right now with one ornery little map that isn't liking going from it's original size of 7" up to 106". Hoping your hint will help it out (but not holding breath, everything else has failed...)