Big Images in a Conference Backdrop

I’m struggling a little. I have a big conference backdrop, and my visuals are big, but not THAT big, so I end up with a little blurriness on an 8’ backdrop. But the printer (ModDisplay) is giving me the impression that “occasionally” people are okay with a blurry image (when you get right up close to it).

My question: Is it pretty standard to have a blurry image on a conference backdrop, since people aren’t looking at it from 12" away? If not, where are all their other clients getting this imagery that’s 150 DPI at 8’ tall?

Here’s the backdrop:

It just needs to look sharp at the viewing distance from which people will be looking at it, which, as you’ve mentioned, doesn’t require the same high-resolution file as one that will be viewed from arm’s length.

This isn’t just a workaround for not having a photo with enough data and detail to be sharp up close when printed as a backdrop or a billboard — it’s the standard way of doing things.

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We print quite a number of 10’ viewing distance backdrops at 35-50ppi, though we recommend about 75ppi for small venues. For video or TV, we go the other direction and drop to 25ppi and intentionally put a heavy blur on the image.

It shouldn’t matter what the drop looks like to the people onstage. It’s all about what it looks like to the audience. Sometimes not even the front 3 rows of audience, depending on the size of the venue.
Print out a chunk of it (tile it if you have to) and tape it to a wall, and step back. Or get a printers proof of a 36" x 36" section if you have doubts.

For an 8’ high drop (by any length) I always go with dye sub fabrics. They give you the most vibrant color punch and there is a slight, a very slight, dot gain to the process that helps with images going large. The other thing is, the dye sub doesn’t reflect stage lighting like a vinyl might.

An 8’ drop isn’t all that large. Is it 8’x8’ or 8’ x 60’? That’ll make a difference in the image you need to acquire.

Here’s the other thing about scenery. If people in the audience are focused on the backdrop, what does that say about the content of the show? While you want the best imagery possible, remember not to upstage what is meant to be the focal presentation of the event.

As with all imagery though, the GIGO rule applies.
Garbage In, Garbage Out.
Get a proof.


That’s reassuring. Thanks.

This is more for a conference booth backdrop, so they’ll be probably 5’ away at the closest.

I enlarged the image in Photoshop, which allowed me to exchange blurriness for pixellation. I think I’ll have to export from Indesign at 150 and see how it goes.

Thanks for the response.

There’s also a psychological thing that happens. People just don’t seem to expect large background prints to be as sharp as small up-close prints. From my experience, unless the image is obviously degraded in a way that calls attention to itself, people don’t even notice — even when five feet away.

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Also, they’re telling me I need to outline the fonts. I’m a little nervous about this, so I’m exporting JPG at 150 dpi.

Thanks for the help, guys. I appreciate it.

no no no.
don’t export from Indesign.
do NOT save as a jpg.

Do your work on the photo in Photoshop. You want to try for a happy medium between blurry and pixelized. Pixelized is generally considered bad form, in effect saying, “I thought this looked good enough.” Gives a bad impression.

Place the image in InDesign.
Outline your fonts. There is no reason to be nervous about outlining fonts for something of this nature.
If you send your file as a jpg, with your fonts rasterized to 150ppi (and your image will be whatever it was in photoshop, InDesign is not an image interpolator) your fonts will not have the nice sharp vector edges they would have if sent outlined.

Did the vendor specify native files with images linked and all fonts outlined? (that would be standard.)
Did they give you the bleed dimension?
Do not forget your bleeds.

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@PrintDriver, let me repeat what you said and see if I understand:

I exported from Indesign, but only after I enlarged the photos in Photoshop (essentially trading blurriness for pixellation; they’re blurry up close, but only very slightly pixellated).

I saved as a JPG at 150 dpi so my RAM/Indesign could handle the file.

I read something that made me think outlining type for the PDF export from Indesign might cause problems.

So, in summary: Are you saying that I should export a PDF from Indesign with type outlined at 150 DPI and send that instead of a JPG?

Thanks for chiming in. I appreciate the help.

What does your vendor want for a file format? Cuz I’d want a native file over a PDF any day.

What your computer can handle and what is required for the job are two different things.
If you are saving out of Photoshop, you should be saving as .psd (or tif, but the psd is smaller, more compact.)
You should place your image in Indesign as a .psd, outline your text, then export to the parameters given by your vendor. If they say 150 press quality with a specified profile, that would be the way to go.

In text heavy documents, outlining fonts isn’t such a good idea. You would lose hinting and would be creating a huge number of data points that slows down production. But on a poster/backdrop with minimal text? No worries.

Unfortunately, the client wants a bunch of small text on this conference backdrop. He wants to be able to brief people from the backdrop…with text. :slight_smile:

Ugh. How small? Surely you’re not setting type at handheld page sizes, right?

As for JPEG, it should always be a very last resort, or, if you work for me, forget you ever knew it existed. Never rasterize type if you can avoid it, outlined or not.

You should be exporting to PDF and packaging the source files too.

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I’d still outline it.
Small text on big backdrop = bad idea, but what can you do.

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Vector type has no resolution. It scales to whatever size is needed at the maximum resolution of the output device without any decrease in quality. Absolutely do not rasterize it. Outline it (which counter to what you’ve heard or read, will not degrade the output on something like this), but keep it in a vector format which will ensure it’s sharp. People might not notice a blurry photo, but they will immediately notice blurry typography

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Sorry, I meant that the whole thing gets exported at 150 dpi. I neglected a comma, apparently.

Good to know about the type resolution. I should pay attention to that. I’m really glad you mentioned that.

Since you seem to be curious about the bigger picture, DPI means Dots Per Inch and is a measure of the dots laid down in printing.

The term I think you’re meaning to use is PPI, which stands for the number of Pixels Per Inch in a raster file. (It’s a common mistake in terminology.)

As a rule of thumb, in standard printing, the PPI should be about twice that of the DPI. In other words, a 300-ppi file is more or less the standard resolution to print out something at 150 halftone dots per inch.

On large format projects like yours, however, the resolution can be a lot lower for the reasons already mentioned.

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Where large format is concerned, the PPI and dpi thing don’t work. There’s no halftone screen to worry about.

For instance, that dye sub machine I use where I print a 75ppi image? Yeah, that thing can print up to 1200 DPI in the head direction. I sure as heck don’t want a 2400ppi file. A good quality running speed is around 600dpi. The print industry isn’t helping at all with the DPI and PPI thing. When they say 150 DPI they mean PPI. They sure don’t mean that’s how much ink is put down. I haven’t heard of any newer model production machine that’ll go that low, even in draft mode. I know the older billboard printers did. Maybe they still do. But they still want 30ppi images for a billboard…

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You know this, of course, but…

A good plate or imagesetter can output at 4000-plus dpi, but both the output resolution of the platesetter and the dye-sub machine are different kinds of dpi than the lines per inch (LPI) of a halftone pattern. One is a measure of output device detail while the other is a measure of the linear frequency of the halftone or screentint dots of the printed piece, which is what the rule-of-thumb formula doubles to determine the optimum ppi of the digital image.

When I send files out for digital printing (not large format), the 250 to 300 ppi rule still mostly applies, even though the halftone dots are missing in the printed piece. It just takes that kind of ppi resolution to get the sharpness needed for up-close viewing.

Tell me if I’m mistaken, but if a large format print is needed where up-close viewing is important — for example a long walk-by museum hallway infographic where the viewing distance would be maybe 18 inches and contain hundreds of thumbnail-sized photos — wouldn’t that kind of sharp output still require similar raster image ppi resolutions as litho printing would require to ensure similar degrees of sharpness and detail?

With large format things like long, walk-by museum hallway exhibits, a couple things come into play.

  • Any text is going to be vector sharp. You want to be sure to not rasterize text in any way.
  • The overall intent has to come into play. Walking by a mural you never take in the full image in its entirety. If the hallway is fairly narrow, where you can’t possibly step back and view the entire image from a distance, you may want to reconsider the angst and effort of producing a single image that size as a design element.
  • If the mural is several vignettes, then you approach do-able resolutions in smaller chunks.
  • Then you get to the mechanics of these printers. Even with smaller imagery, like 4x8 foot chunks, your machine optimization isn’t going to get much above the 200ppi mark. Usually 150ppi is the cut-off for close up work. The reason is, even if you increased the image resolution to 300 or 400, you don’t get enough of a difference in quality to make all the extra ppi worth it. Both in time and money. More resolution takes longer to render on your computer, so it takes more billable time to work with, and it takes longer for the printer to rip and they will charge you an upcharge if you insist on the high ppi.
    Even with a con-tone lambda printer, we still look for 200ppi as optimum for imagery. With a mural, that can come down to 100-150, though I have gone lower on murals that were meant to be wayfinding up close, but maybe viewed from across a room as a whole wall element.
  • and of course there is file size. Even though photoshop as the .psB option, there isn’t a lot you can do with that. You can’t place it in Illustrator or InDesign. That leaves you the option of printing it raster from Photoshop, or working with your printer to work out a reasonable workaround.

Art prints are a whole different ball of wax. In the case of art or more specifically photographic art, then you are aiming for as much resolution as possible, both with input and output. Take the average industrial high-end inkjet printer and you would be looking at something around 600ppi for input and asking for the machine to be run on the slowest possible fine art quality speed giving the highest DPI output. These things print using variable droplet sizes measured in picoliters. You also pay serious cash for these as they can take a very long time to print compared to the “consumer quality” normally printed.

One of the biggest mistakes a newb to the print industry makes is buying a machine based on maximum throughput. Those max square-footage speeds are not salable prints. They look like crap even in what is called “production mode.” A print machine has to have 2 to 4 slower speeds (higher dpi modes) that are fast enough to produce the best product in the least amount of time.

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I’m really glad you guys keep pounding home the idea that text really needs to be sharp. I’m gonna make that happen. Thanks.

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