IMPORTANT! Prepare images BEFORE placing them into the PowerPoint slide or other graphics canvas use to prepare the poster. Images and canvas (slide) need to be at the same resolution, at the printable size to avoid distortion of the images.
When using the SOAR poster template (PowerPoint) or any other software for creating a poster, if possible, make all images high resolution for the size that you actually want it to appear on the poster. This may be rendered moot by the RIP software that we use, but it is still the best practice when printing images, whether on posters or just by themselves. By starting with the highest quality images there will be less image/resolution manipulation to do.
It is generally better NOT to increase the resolution of images, unless it is the last alternative. When you do this, the software is ADDING PIXELS THAT ARE NOT IN THE ORIGINAL IMAGE and by doing so, you increase the likelihood of printing artifacts, degrading the final printed output. It is far better to start with a good, high resolution image to begin with and then throw out pixels, if necessary, to get to a usable print resolution. In the case of the Epson Stylus Pro 11880 printer, in the Art department, that print resolution is 240 ppi.
If you are using Photoshop, or Painter , or another graphics software, use 240 ppi when setting up the canvas. Then make sure all images are sized and saved at 240 ppi BEFORE you add them to the canvas. This will result in your final, flattened, image being compatible with the printer’s output resolution of 720, 1440 or 2880 dpi.
For more information see Advice for Making Posters with PowerPoint.
To prepare images In Photoshop:
- From the menu across the top of the page click on Image.
- From the Image menu, click Image Size and from the dropdown menu at the bottom of the dialog box. If your image is close to the size and resolution you want, then choose:
- Bicubic Smoother (best for enlargements)
- Next check the boxes:
- Scale Styles
- Constrain Proportions
- Resample Image
- Set the size and resolution and save.
If you need to increase the size or resolution of the image by more than 20%, increase width, height, and resolution in 20% increments, saving each time you increase, until you reach your desired ppi (220, 240, or 300 ppi).