This is how I spent most of my morning--sketching kitchen elevations and dining room built-in options to show custom cabinetry studio tomorrow.
pens to sketch or draw with EVER!!! I discovered these while in design school and have one or two with me at all times. Yes they are waterproof, document proof, fade resistant, blah blah blah but the best thing about these markers-- they can be left uncapped for 18!!! hours without drying up.