Watercolor illustrations for printed wallpaper quality

Question

It's my first time working with printed wallpaper and my client wants several watercolor-style illustrations (I add 2 examples of the style they want) for walls of 490cms x 260cms (divided into 7 rolls) that they want to print them at 300dpi, so they prefer vector graphics they can scale without problems. What's the best way to work this out?

I've only worked with large graphics in which 100dpi/150dpi it's enough because you'll see them at a fair amount of distance, so creating something this big at this resolution is a bit confusing. Do they really need the 300dpi?

I mean, it makes more sense to work the watercolor style in Photoshop but I won't get far in terms of size/resolution and vectorizing the watercolor art on Illustrator although possible, doesn't offer the same visual quality, especially considering that you will be able to see all its details if you stand next to it.

Thanks in advance.

Answer 1

No, Do not vectorize them.

Doing a large project in a raster format is not contradictory to assembling it in vectors.

On the examples above:

• Paint the bear in raster. Only bear+baloon.

• Paint the aerostatic balloon, only it.

• Paint the branches of the tree.

Make calculations for what pixel size you need them.

• The background could be at a lower resolution because it does not have sharp edges. Define if you want the clouds also as separated files.

Now you have only one element at a lower resolution, (because it does not need it) and some other elements at higher one with the respective transparency.

Assemble all of them on a file, let's say on Corel Draw which allows preparing a big canvas, or on Illustrator at a scaled file, let's say 1/4. The bear will be at 1200PPI

Now you have the right file to work with.

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And no. The truth is that you do not need 300PPI.

300PPI is used on a commercial print as the double of the final resolution in Lines per inch LPI which normally are 150 in a good quality print, (a magazine, a poster). On an expensive art book you could have 200LPI wich needs 400PPI on the file, but the end result is 200LPI.

On photographic prints, 200PPI is enough, because it does not need to be transformed.

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On a case like this I do recommend doing the elements at the real size at 300PPI but only to give you room to work with the final composition. The bear a bit larger if needed.

But in some other cases where the images are computer-generated, like a 3D render, this 300-200PPI difference translates into more than double computer processing time:

• 2x2=4
• 3x3=9

So I would go for the exact size.

On a digital paint, it could be a difference if working with a big file 300PPI, your strokes become choppy, then try a 200PPI file and see if they are more fluid.