4K HD Wallpaper: The Magic Pen
Photography took by Aaron Burden and shared from his courtesy under CC0 license. If you need an image with a pen which is also free this one looks really good. Here's optimized for use in desktop backgrounds, homescreen phones (looks great), social media campaigns, web design projects, blog articles...
Widescreen Desktop / Macbook (Retina): 2880x1800 (fits on: 2560x1600, 1920x1200, 1440x900)
High Definition HD 1080p: 1920x1080 (fits on: 1600x900, 1366x768, 1280x720)
Samsung Galaxy Tab & iPad: 2048x2048 (compatible with many tablets)
HTC, Samsung Galaxy & iPhone: 1080x1920 (compatible with many phones)