Producing smooth gradients with a pen is a technique that will increase a sense of realism and depth on your drawings. Architectural Drawings: Use these techniques to differentiate materials and surfaces in architectural drawings, such as the brickwork of a building or the feel of a road. Fountain Pens: https://daltonltwpd.mybuzzblog.com/17158641/how-much-you-need-to-expect-you-ll-pay-for-a-good-ink-drawing-for-beginners