Is it bad if the PPI of a graphic is much larger than 300?

[Mateomono]

Hi, 

I am working on graphics and diagrams for a book layout and when I place them in InDesign, the PPI is much higher than 300. Does that matter, or is it not an issue as long as it's above 300?

The graphics are very simple, mostly just shapes and lines.

Thank you!

[James Gifford—NitroPress]

Since nearly all ID projects are exported one way or the other, usually to PDF for print, and the export process is usually set to optimize graphics for a particular end result... no. Having an effective PPI higher than 300 is usually a good or at least benign thing.

If you're working with really large images placed really small, so that you end up with huge effective PPI (1000 or more)... it's still good, but it may be worth reducing the largest ones to save file space, processing power and generally take a load off the export process. But 300-400 effective PPI is still your goal.

(Unless you're exporting to 600 PPI for some reason — in which case you want at least that in your effective values. But 300ppi is the working standard for nearly everything including high-res process printing.)

[Willi Adelberger]

Graphics should be not pixelated images at all. You should either use PDF/X-4 or AI files. 
Images higher than 300 ppi will be recalculated as the joboption definition is set up. A higher resolution than the defined threshold will bevrecalculated and not cause a better quality, but the contrary is the case. The downrecalcatinf can end up in a worse quality. 

[James Gifford—NitroPress]

I missed the line about images being shapes and lines — perhaps an edit there?

It's also not clear whether the OP is intending this for print, PDF, e-book or other destination..

But yes, diagrams, charts and the like are best created as vector elements, either AI or PDF, so that export resolution to PDF/print is maximized. OTOH, 300 ppi/dpi is likely what's going to come out of that process, so well-formed 300ppi raster images would be hard to tell from vector in most cases. But best to use a vector format (which it probably is in the image source file anyway) for best results.

[Robert at ID-Tasker]

@James Gifford—NitroPress

I would disagree - 300ppi bitmap version of the original vector will look much worse when printed.

[James Gifford—NitroPress]

I wouldn't disagree, out in the direction of 'best options.' But it all depends on the OP's workflow and end goals. An optimal 300ppi image can be indistinguishable from what's rendered to that same 300dpi final output unless there are some very demanding elements (fine lines, shading, etc.) and then a commercial printing process might make it no difference at all. 🙂

No argument that vector for PDF management at export is superior with few exceptions.

[Robert at ID-Tasker]

@James Gifford—NitroPress

From what I know - vector elements are rasterized - on the RIP - differently than bitmaps - with the max available resolution - so the difference in quality will always be visible.

[Dave Creamer of IDEAS]

That's basically correct but everything outputs at the RIP resolution. It's just that the raster (pixel) images are broken down into pixels before then (except for 1 bit images saved in the correct format). The pixels are rasterized at the RIPs resolution.

[Dave Creamer of IDEAS]

Depending on the graphic and paper, it may be noticable to the trained eye, but most people probably won't notice it. Back in the early 90s, I had a vector art that was too complicated to print. I rasterized it in Photoshop at 300 ppi and the rasterizaton on even the black type was barely noticable. 

[Robert at ID-Tasker]

@Mateomono

Can't you have them as vectors? 

[Mateomono]

@Robert at ID-Tasker 
Is that possible? I was under the impression that you cant for print project. Also by vectors you mean placing them as svgs?

[Robert at ID-Tasker]

@Mateomono

Can't what? Use vectors? Of course you can. And if you have vector version - then you SHOULD use it instead of a "bitmap". 

SVG is one of the formats - but there are many more - the best one would be AI / PDF - which, technically, is the same. 

[Dave Creamer of IDEAS]

Vector is the preferred format unless the art can't be created that way. 

I would not use SVG for print however. As you say, AI or PDF would be better.

[Willi Adelberger]

SVG is only for web projects, never for print.

Use PDF/X-4 or AI files for vectors for print.

[Mateomono]

@Willi Adelberger 

So I should just export it as an AI file and then import that ai file into my book layout, right?

[Robert at ID-Tasker]

So I should just export it as an AI file and then import that ai file into my book layout, right

By @Mateomono

Export from what application? 

[Mateomono]

Illustrator

[Robert at ID-Tasker]

Illustrator

By @Mateomono

Then you don't have to do anything else - just place the file in InDesign. 

Place - as Ctrl+D - do not copy&paste or embed - it needs to be linked. 

[Dave Creamer of IDEAS]

You don't "export", you simply save the file (with a PDF preview). Then Place it in InDesign. 

[Dave Creamer of IDEAS]

Generally, an image with TOO high a resolution can look slightly soft.