Hi
🙂 6" x 4" is not very useful in this context as it is a size measured on paper.
You need to use a digital image measurement. e.g. 1920 x 1080 pixels (2 Megabyte image) or 4480 x 2520 pixels (11 Mb image ) etc. The higher the resolution in Mb the clearer the image will be.
You will have your image in the image clip bin.....Right click it and then at the bottom of the list click Properties. Check what values you have against Dimensions. This will give us an idea of what size of image you are trying to use.
How did you get the image you are using?
Nat