Resize a drawing to print it (doubt)

[baronesbc]

Hi, I made a painting on artrage 4.5, its format is 135.47 x 36.69 cm (3840 x 1040px 72 dpi). Now I would like to print it on a canvas, so I tried to resize the drawing bringing it to 225x60 cm (26576 x 7197px 300 dpi), but I suppose this to lose quality when printed, although apparently (on the PC screen) do not seem changed anything.
I would not have nasty surprises after I printed it, so I would clear my head a bit '.
Thank you. Sorry my English.

[Veni, vidi, Da Vinci]

Hi baronesbc!

You can only assess the printing quality of the picture on your screen if you watch the picture in the zoom-factor 1:1. To scale a picture as much as you did will definitly lead to a bad quality, I think. Upscaling always reduces the quality of pixelbased pictures, depending on the scaling- and some other factors. So you should always paint in a useful size, right from the start. But most big pictures, like posters, are printed in a lower relative resolution (Pixel per Inch), with bigger dots, because usually nobody watches them from a close distance. So you don't need to paint pictures with tenthousands x tenthousands of pixels until your computer crashes. You can reduce the relative resolution of your picture, depending on the intended target dimensions. The absolute minimum is, as far as I know, 100 Pixels per Inch. The resolution in pixels x pixels should stay the same when you do this, but the dimensions in Centimeters should change automatically. Unfortunatly ArtRage seems not to compute this correctly in it's "Print Size" dialog box. Maybe a bug. But you can use another software for this, for example GIMP. It has a dialog box called "Print Size" especially for operations like this, that does it correctly.

But to make no mistakes, I think it will be better to talk to the company you like to order to print your picture. I took my informations from the website of a german printing-service. Maybe other companies use other standards.

Hope my english is not too bad and I could help you a little!

[baronesbc]

Hi baronesbc!

You can only assess the printing quality of the picture on your screen if you watch the picture in the zoom-factor 1:1. To scale a picture as much as you did will definitly lead to a bad quality, I think. Upscaling always reduces the quality of pixelbased pictures, depending on the scaling- and some other factors. So you should always paint in a useful size, right from the start. But most big pictures, like posters, are printed in a lower relative resolution (Pixel per Inch), with bigger dots, because usually nobody watches them from a close distance. So you don't need to paint pictures with tenthousands x tenthousands of pixels until your computer crashes. You can reduce the relative resolution of your picture, depending on the intended target dimensions. The absolute minimum is, as far as I know, 100 Pixels per Inch. The resolution in pixels x pixels should stay the same when you do this, but the dimensions in Centimeters should change automatically. Unfortunatly ArtRage seems not to compute this correctly in it's "Print Size" dialog box. Maybe a bug. But you can use another software for this, for example GIMP. It has a dialog box called "Print Size" especially for operations like this, that does it correctly.

But to make no mistakes, I think it will be better to talk to the company you like to order to print your picture. I took my informations from the website of a german printing-service. Maybe other companies use other standards.

Hope my english is not too bad and I could help you a little!

thank you! I thought That to print it on a canvas would mask the problem of the quality, this really helps?
Is there a way to make sure of the quality before printing?

[Veni, vidi, Da Vinci]

Excuse me, I made a little mistake. I use to think in Millimeters when I paint or manipulate pictures on the computer. You use Centimeters. In fact your painting is 32,512 Centimeters x 8,805 Centimeters big in the standard-resolution for print (300 ppi) - not as small as I thought. But not big enough to upscale it to 225 cm x 60 cm, I think. It's better to reduce the relative resolution (pixel per Inch) to look how far you can go. But you shouldn't reduce the resolution to less than 100 ppi. Some say 150 ppi is the minimum. With 100 ppi your picture would be 97,536 cm x 26,416 cm big. With 150 ppi 65,024 cm x 17,611 cm. So it should be no problem to print it as a poster. But not the size you intended, I'm afraid. Hope you have a copy of your painting in the original size.

It's because pictures that are created in ArtRage (Photoshop, Paint Shop, GIMP...) are based on pixels. Pixels are small squares. Every pixel can have only one color. So a pixel picture is a kind of a mosaic (or "tesselation"? - don't know the right word in english). These pixels must be so small, that the human eye is not able to discern them as single picture points. So you need a minimal number of pixels per Inch. And you need much more pixels for pictures that are meant to be printed then for pictures that are just made for the screen. Because of that 300 ppi is the standard for print. The total amount of pixels relative to this 300 pixels per Inch defines the size of a picture in Centimeters. If you upscale pictures, even the pixels will be upscaled, so that the single pixels become visible or, if you use Interpolation, the picture will become blurred. This is the main reason why the quality of pictures gets bad by upscaling. And the quality declines by every single scaling.

But to feel certain you should ask an expert, preferably from the company you will order to print it.