I’ve been Googled about this for a long time but never got any answers. This is a thing that is always misleading when it come to formality. I understand the concept of fabrics and that some prints/colors are less formal/professional than others, but the trickiest part is when it comes to garments that has more a formal cut like shift dresses, pencil skirts, blazers but their print and fabric is not consider formal. Such as a corduroy and floral pencil skirts. Its really confusing whether you should go for the fabric/print or the cut of the garments like this when up/down grade them. I mean, just because its corduroy, I feel very skeptical about wearing sneakers and cotton tops with the pencil skirt. I only wear canvas sneakers with short bodycon, ruffled and denim skirts personally…
If you think about Levels of Refinement - can wear clothes from two levels at once to dress up or dress down an outfit. So canvas sneakers (like Converse) will make a pretty floral dress look more casual vs putting that dress with a heel, which would dress it up.
That said, prints and fabrics can change how formal a garment appears.
With prints – the larger, the higher contrast, the more random the print (less ordered) the less formal the garment becomes. The more colours you add to a pattern, the less formal the garment appears too!
Generally, the more textured the fabric, the less formal it becomes. The lighter the garment, the less “work formal” it appears as dark colours convey more authority than light colours.
Straighter lined garments are more formal then curvier garments because straight lines convey more formality and structure – this is why a straight skirt appears more formal than a circle skirt.
Have you noticed that most formal dresses (think red carpet events) are usually solid colours rather than patterns? It’s because they are a formal garment for a formal occasion. Notice the fabrics, they are shiny, or fine and floaty.
So the reality is, you are always weighing up all the elements of a garment at once, the print, the fabric, the texture, the colour/s, the sheen etc. when deciding on how dressed up or down it is and whether or not it’s appropriate for that situation. In the end the answer comes down to your personality, lifestyle and the occasion as to what you should wear!