We are hiring an illustrator for a project which will have components in both Storyline and Rise 360. We want to use those images in both products. While experimenting I uploaded a stock image into the banner section in Rise 360 and it is blurry. I need to know what image size and what type of file we need the illustrator to convert our images to so they work best in both platforms. Are there resolution and pixel dimensions that work best? I read that .png files are preferred to jpeg, is this true?