Resolution for printing

[DJM]

I have AR on both my desk top and my iPad. On the desktop you pick your resolution when you choose your paint size. Can this be done on the iPad/tablet ? I was thinking about printing some work I have done, the printing place wants to know what resolution I will use and prefers 300 dpi not the 72 dpi used for internet. So, is 72dpi a tablet resolution ONLY ? Or can I do 300 dpi?

[markw]

Hello DJM,
I believe you can’t edit a canvas size once made in the mobile versions of AR. But whether you can you set dpi/ppi when setting up a new painting I don’t know?
Any way, what really matters for printing quality, no matter what app is used, is how many pixels are in your painting to start with, ie, Hight in pixels by Width in pixels.
The dpi/ppi is the meta data attached to an image to tell a printer what it should be aiming for when printing.
Here are some links for further reading:
How to pick a Canvas Size for your ArtRage Paintings: https://www.artrage.com/manuals/the-...ick-reference/
Canvas Size Properties: https://www.artrage.com/manuals/work...d-canvas-size/
Scaling Up Your Mobile ArtRage Artworks For Print: https://www.artrage.com/manuals/work...ile-paintings/

[DJM]

I have not read the links you took the time to send, I will. Hear is what I am thinking, if you are to use 72 psi as a base for internet images then an 8x10 image would have 80 sq inches and using 72 psi then that should relate to a 576x720 which would equal 414720 divided by 80 which is 5,184 pixels in a 8x10 image. Would this or does this make sense? My next problem will be transferring an image from my iPad to a memory stick. A proper cord if available would be the way to go, and from what I am told they are expensive ($80.oo). Thanks for your help

[markw]

Hi DJM,
Yes, your maths dose make sense.
But to the question, are there enough pixels in that example to make a good 10 x 8 print, then the answer is No. Printed 10” x 8” at 72dpi it would look awful close up.
For a quality 10 x 8 print the sauce image would ideally be around 3000px x 2400px+/- and so made up of around 7,200,000px +/-
That’s quite a lot more than the 414,720px in your example.

Fortunately as you know in AR we thankfully don’t have to do all this complicated maths when setting up a panting as the software can figure out the optimum pixel requirements for us. But for it to do this we do have to specify a dpi/ppi value for it to work with.
So it’s important to know how the chosen ppi/dpi value may effect our print size choices later on.
It’s only when we have an already finished painting who’s pixel dimensions are already set that we have to do some maths to work out if it would produce a good print.

I mostly work in AR aiming to print to A3 size and so a typical canvas size for me in AR would be 3508px+/- x 4961px+/-.
From past experience, and what the printers tell me, to get a good visual result when viewed from a few inches to 3’ or 4’ I need to use a dpi value of 300+/- when printing.
At the risk of muddying the waters however, I would also say that high dpi values are not always needed when printing if the final viewing distance is going to be a long way off. For example if I wanted to make a large billboard poster that was generally going to be viewed from at least 20’ or more I could use a dpi of 100, or lower.

It can take some time to get ones head around all this but eventually it becomes intuitive as to whether something will give a good print or not.
Do read up about printing and not just from the links I put up earlier.
Colour accuracy when printing, between what ’s on our screens and what is actually printed is a whole other important minefield…

[DJM]

Thanks Markw, your reply is greatly appreciated and to the point. I noticed under techie stuff that you are using a 15” MacBook Pro and that setting dpi is possible with a laptop. I use my iPad Pro, this is a hobby for me. The pad is by me at breakfast and easily accessible for a one hour session. The thing is, the the pad pro version of AR doesn’t allow you to set dpi, just hieght and width in pixels, I my be wrong on this point, I’m not sure. I have read the links you mentioned and will reread an d take notes. This is whole new learning process and may take me a bit to get to actually printing something. In the mean time, thanks for your help.

[markw]

Hi DJM, only to glad to help where and if I can
Sadly yes it’s true I don’t have an iPad but I did find this video on YouTube that shows setting up a new canvas on an iPad:
https://www.youtube.com/watch?v=LEUbMwsxsco
It looks to me like you can only set up the canvas size in pixels so actually setting a dpi value here would be meaningless without also being able to specify a real world size.
So yes you will have to do a bit of maths to work out how big you could print something in terms of real world measurements and still have it look good close to.
For example if the max pixel size you can set is only 2048px by 2048px and after exporting the finished piece you give it a dpi of 300, it would print out about 6¾” x 6¾”.
If you were to drop the dpi to 200 for printing you would get a 10¼” x 10¼” print.
Now depending on your painting style, if it’s a bit loose and/or soft say, 200dpi could still give you an acceptable 10¼” print.
So be prepared to do some experimental prints and see what actually works for you.