We haven’t done one of these in a while, but a reader requested one in a comment on the ‘How to pick shirt fabric’ article, and it reminded me how useful people find the sliding scales. 

The idea is we break down two categories of clothing in terms of how formal the types are, and then pair them up, helping readers understand what contributes to formality and how the two go together. 

The first one back in 2008 looked at trousers and shoes. It broke down the different types of trouser material from worsted to denim, and suggested what types of shoe - from an oxford to a deck shoe - were most suited to them. When you’re first starting out, formality ideas like this are often a good thing to work through.

There was an update to that piece in 2022, where we expanded the range to look at shoes and tops alongside trousers. And there was one on hats and coats, plus of course the related ‘Which office are you’ series. 

Formality is only one small part of what makes clothes go well together, but as that recent comment showed, it’s one readers still struggle with. So here’s a new one - as requested - looking at shirts and suits. 

Below is a basic categorisation of different suit materials, in order of formality. Then there’s one of shirt fabrics, again in order. 

Following this we have a matching of the former and the latter, using their numbers and letters to show which goes with which. Then there’s the wonderful world of all the many and varied caveats.

Suit materials 

1. Superfine wools / mohair
2. Other smooth, business worsteds
3. Serge / coarser worsted / high-twist wools
4. Flannel
5. Linen / smooth cottons / seersucker
6. Corduroy / tweed

Shirt materials

1. Superfine cottons / silk 
2. Poplin 
3. Twill / cotton/linen
4. Linen / brushed cotton
5. Oxford
6. Denim / Chambray

Suggested combinations

1 : AB
2 : ABC
3 : BCD
4 : BCDEF
5 : BCDF
6 : DEF

So this pairing suggests that a suit in something sharp like a superfine wool or mohair (1) is best matched with either a similarly silky shirt material (A) or a cotton poplin (B) - probably the smartest of cotton shirtings. 

If any of these terms aren’t familiar, by the way, they are all explained in the Permanent Style guides The Guide to Suit Cloth and The Guide to Shirt Fabric.

Unlike previous articles, I’ve done these combinations by matching each suit to several shirt fabrics, showing the range of suitable options. This could of course be reversed by starting with the shirts. 

This is a more helpful way of explaining things than trying to match one for one, I think. It also shows how little of this is a question of hard lines - everything is rough and, at the edges, sometimes a question of personal preference and style. 

Now the caveats. The big one is that there are lots of subtleties and sub-categories that we cannot include without the list becoming unmanageable. 

A royal oxford fabric, for example, is actually very smooth and smart. ‘Oxford’ just refers to a weave, and what yarn you weave it with makes a big difference. But we cannot include more without the list losing its ability to communicate. 

And anyway, the point of the article is not for readers to go away and use this as a checklist to literally pair each fabric together. Instead, it is one way to understand the principles of what makes something smart or casual - its smoothness, its texture, its shine - and then apply those to any such combination.  

It doesn’t matter that royal oxford isn’t in the list. Because once a reader understands the existing pairings, they can look at a royal oxford and see how much smoother and finer it is than a regular oxford, that it’s probably nearer to a twill in terms of smartness. 

Here are some other useful caveats:

• Colour and pattern make a big difference to formality obviously, and we haven’t covered those. More colour and more pattern are generally more casual
• The same goes for design. A spread collar is smarter than a button-down, a double-breasted suit is usually seen as smarter than a single-breasted
• The list doesn’t include jackets, but it wouldn’t be hard to do something similar. I might put wool/silk/linen alongside serge, for example, and cashmere alongside flannel

And some observations:

• Linen suits I find interesting, as they seem to have the widest application - I’d wear everything with them from poplin to denim. Perhaps it’s because linen feels like a material that is trying to be smart, but just has to make sacrifices for the heat
• Season is another variant not considered here, and is the only reason I wouldn’t pair a linen suit with an oxford shirt - just because there isn’t a summer version on that formality level
• Associations like this make such a difference. For example, we associate barathea with a dinner jacket, and perhaps covert cloth with country clothing. Yet the latter is in some ways a smarter material, given its sharpness
• By ‘smooth cottons’ I basically mean, not corduroy. As with everything there are many sub-categories we can’t include, such as moleskin, brushed twill cottons and so on. 
• To me the separation between poplin and twill shirt fabrics is understandable but sometimes unhelpful. Both vary so much in their fineness, as well as colour, pattern and so on, that it’s something I’ve found readers get too hung up on.

I could go on, but that would take away the fun of letting readers pick their own holes in all of this. I’m looking forward to it. I think.