Last year I did cover this topic in some detail during a livestream inside my Edges course (Refer to Livestream 7 2021 in section 4.18 of Edges) but these sketches summarise those thoughts.
A few comments that relate to these sketches
- Draw as much detail as you can depending on the scale of your drawing. There is a frame to the opening as well as a frame around each pane, and then sometimes additional mullions.
- Make sure you understand how foreshortening affects windows – often you see more of the sides of the wall opening than the window itself (more about that in Buildings Intro Lesson 2 and this article.)
- Make sure that any window/glass treatment fits in with the rest of your sketch (the amount of detail, the colours, the values etc)
- Avoid blobby paint for glass – instead ensure crisp edges. Sometimes the easiest way to achieve this is to apply opaque white over the top of your glass washes. My preference is white gel pen – Pentel Signo Broad.
- The glass in windows on the upper levels of a building reflects the sky and the glass on the ground floor level reflects the surrounding buildings or trees. This page shows black-ish reflections but they are not necessarily true black or as solid as I’ve shown on these diagrams.
- Furnishings (curtains, blinds etc) result in white-ish windows – I normally use a pale turquoise wash (Cobalt Turquoise Light) as this colour makes me happy.
- There are often shadows cast by window /window framing onto the curtains/blinds.
- I often adjust the position of blinds to suit my sketch ie. if all the blinds are pulled down making all windows in a building white, I often raise them in my sketch and create variety!
- The glass on the shaded side of a building is often lighter than the glass on the sunny side due to reflected light.
- Shop fronts can be complex – but my current approach is to draw/paint the interiors first (no ink) and then add or adjust for reflections (particularly lighter reflections) afterwards.
If you are wanting some tips on skyscrapers and glass reflections:
Hope these thoughts are helpful! There is more to the topic but these are the main considerations and techniques that I use.