Use the word unmarred to describe anything without a single flaw or injury. Your unmarred apple pie looks perfect — although it collapses as soon as you cut into it.
A field of newly fallen snow is unmarred until your dogs go barreling through it, running in crazy circles. And if you drop your favorite mug on the floor, you'll be relieved to see it's unmarred, without a single scratch or chip. To mar something is to mark, scar, or scratch it, from an Old English root that means "to spoil." When its unmarred, therefore, it's free of any marks that might spoil the way it looks.