In order for us to print a poster of your painting, you will need a digital copy (print-file) of your original painting.
This can be achieved in one of two ways:
- Method 1: Scan the painting
- Method 2: Take a photo of the painting
If you do not want to pay a specialist photographer or print workshop to create a digital copy, we will go through both options (scanning and photographing). We will tell you which method is best and how to achieve the best result.
If you have already captured or scanned your painting, you should go to our guide. “How to export a print ready file in Photoshop“.
This guide is made for Kræss x Purpleposter artists. Sign up and sell your artworks at Kræss x Purpleposter. All you need is a print file of your artwork. We print and sell your artworks as posters online and in our physical store. Sign up here and join 140 other independent artists.
Before you look into the two types of methods, you will need to consider 5 important attributes of a digital copy in order to achieve the best possible print.
The resolution is the size of the canvas of the file. If you need to print your artwork on a large poster you will need a high resolution to avoid rasterization. We suggest minimum 2500 px on the shortest side for A3 poster sizes (29,7 x 42 cm.).
= Set the scanner or digital camera to produce the highest possible resolution.
It is important that the digital copy looks exactly the same as on the print (paper) and on the screen. This can be difficult as a computer monitor or mobile screen displays the colors very differently than ink on paper.
Printers used to only have 4 different ink cartridges (C, M, Y and K) reproducing less colors than a digital screen. Therefore digital copies should only contain colors that could actually be printed, in order to avoid the screen-version and the paper-version to look different. This is a limited amount of colors (color profile) called CMYK.
Today modern printers contains 10 or more ink cartridges and can reproduce many more colors. The best printers can reproduce almost as much color as a digital screen. Therefore we suggest to create digital copy in AdobeRGB color profile, which is a large color space that contains many colors and used for modern digital screens and printers. If you can only print on a older printer using CMYK, you can always convert the color profile to CMYK later on.
= Set the color profile to AdobeRGB or a color profile with a even larger color space (e.g. ProPhoto). It is great to have the original copy (file) with as much data as possible. When exporting the final digital copy to be printed and shown on a digital screen use AdobeRGB color profile (if you printer can manage). Consider to convert from AdobeRGB to sRGB for you digital screen copy (smaller color space and safer for most screens).
Image bit-depth (e.g. 8-bit or 16-bit) also determines how many colors will be shown on the screen and the print. The image bit-depth is mostly noticeable in posters with gradients.
A rule of thumb is to set the highest possible image bit-depth. However many printers, scanners, cameras and software can only use 8-bit and many image-files formats (JPEG e.g.) can only show 8-bit anyway. But still we think you should go for as high image bit-depth as possible as technology is always evovling.
= Set the Image bit-depth as high as possible
Print file format
The most common files to use for print-files is PDF or TIFF. They all contain as much data as possible so you are able to print in a high quality.
TIFF is great as it is a universal image format that can be processed in almost every printer and image software editing program.
Some people prefer PDF because the data can be compressed and the file size is less than TIFF. However not all printers can process PDF, and you will also need to save it in a proper high quality PDF file format (there is many version).
We usually store our print files as PSD (which is a Photoshop file format that contains as much data as TIFF). The PSD is easy to process in Adobe Photoshop and Adobe Lightroom. We convert the file to TIFF before sending it to the printer.
= Create the print-file in .TIFF format.
Post editing software and monitor
When you have scanned or photographed your painting, you most likely will have to post edit the print file using an image editing software like Photoshop to color correct the file to make it look as similar as possible to your original painting (adjusting contrast, light and colors).
Photoshop is the market leader and preferred image editing software for most professionals. For a free alternative to Photoshop check photopea.com (a free web browser version of Photoshop).
When you edit your print file in Photoshop or another image editing software is it very important to crop the image to have the same aspect ratio as the final poster you will print. E.g. an A3 print is 29,7×42 cm. That makes the aspect ratio 1:1.41 (height divided with width.). Otherwise your final poster will look as if it has been extended or abbreviated.
You will also have to use a monitor (computer screen) that shows colors correctly, so the print does not come out in different colors compared to what you see on your monitor. Beside using a good monitor, remember to set your image editing software to only show the same color space (color profile) as is available to reproduce on your printer (read above about color profile).
Professional monitors showing colors perfectly (like Ben Q monitors) will cost a lot of money. Apple computers with Retina monitors will work fine for most people.
We have made a detailed guide on how to create the perfect print file in Photoshop with all the right settings such as color profile and aspect ratio. Go to the guide.
Scan the painting
Pros: Very high resolution. Easy and Quick.
Cons: Difficult to scan large paintings.
Scanning the painting will achieve the highest resolution. Even low cost scanners on top of office inkjet printers can produce high resolution.
However the color space (color profile) of the scanner might not be very large (most likely sRGB), and you will properly also have to post color correct the print-file in a editing software like Photoshop. Especially strong colors (like neon) might be off.
However if it is a good quality scanner made for artworks, the colors will be very good (as no natural sunlight or any other light effects the scanner. However these printers are very expensive.
The file format of the generated file might also only be in JPEG or PNG and have a low image bit-depth. This is not the biggest issue as even JPEGS can have a “good-enough” quality for printing posters.
It is very hard to come by scanners suitable for painting larger than A4 size (21×29,7 cm.) paintings or at least they are very expensive. Usually an A3-scanner costs 2000$ or more.
If you want to scan a painting larger than A4 – lets say; a A3 size (29,7×42 cm.) painting which is double the size of a A4 painting, you could break up the scanning into two. First scanning the top and then the bottom of the painting. Afterwards you could put the two pieces together in an image editing software like Photoshop. However this would require a lot of time and effort to produce a good result. It is difficult to put them together perfectly.
Also note that it can be difficult to scan the image perfectly if you have a use a lot of painting (thick) or your canvas is not very flexible. You will most likely have to put force when closing to lid of the scanner (use heavy book e.g.)
Take a photo of the painting
Pros: Very high resolution.
Cons: Difficult to scan large paintings.
If you do not have have a scanner or if your painting is to large to fit your scanner you can photograph the painting.
Photographing your painting requires a lot more effort, as it has more variables (light condition, shutter speed, cromatic abberation, white balance etc.). All of these variables you will have to adjust yourself before and after taking the photo to make the digital copy of your painting look as close as the
Where is the scanner is a quick closed-in (press and scan) process in a enclosed space with no influences from the outside, a lot more can go wrong when photographing because of the outside influences such as light conditions and camera gear.
If you photograph your painting we suggest to:
- Use a good DSLR camera or mordern mirrorless camera.
- Use good light with a specific temperature so you can adjust the white balance.
- Luminate to painting evenly with your light.
- Do not use ISO above 800 (too grainy). Instead use more light.
- Shoot RAW.
- Set the camera color profile to AdobeRGB or ProPhoto.
- Set the shutterspeed to less than 1/250 (best clarity)
- Use a good lense at a prober distance to avoid cromatic abberation
- Make the painting fill as much as possible of your photography (best resolution).
- Remember to focus on the painting (use auto focus).
In this guide we will not go through the technical steps of a the camera, but there are plenty of great camera guides on Youtube, like this one.
It is always best to scan your painting. It is much easier and quicker. It also produces a higher resolution even on low cost scanners. But you will still need to color correct the print file to make the colors look exactly like your original painting.
In many cases it is not possible to use a scanner, because a painting is simply to large to fit.
Then your only option is to photograph it. This process is a lot slower and a lot more variables can go wrong (colors, light, contrast, lens, white balance etc.). However if you have a good camera and lightning conditions you will be able to capture a nice illuminated photo of your painting, and if you have the patience in Photoshop to crop and color correct the photo to make it look like the original painting, then the result can the quite good. Even though the resolution will not be as good as if you have had a scanner, you might still be able to print a poster as large as A1 size (59,4×84,1 cm.).
This guide is made for Kræss x Purpleposter artists. Sign up and sell your artworks at Kræss x Purpleposter. All you need is a print file of your artwork. We print, promote and sell your artworks as posters online and in our physical store. Sign up here and join 140 other independent artists.