Short answer: a vest goes under a blazer when it is knit, thin, and quiet. Fleece, quilting, and logos are the three things that make the combination fail, and most vests have at least one of them.

I own Ritter and I have watched a few thousand men try this, so here is the honest version.

What the blazer needs from the vest

A blazer is cut to sit over a shirt. Anything you put between them has to behave like a heavier shirt, not like a second jacket. That means:

• Flat, not puffy. No baffles, no quilting, no down. A knit or felted wool vest compresses to almost nothing at the shoulder seam, which is where a puffer fights the jacket and pushes the collar up.
• A knit or wool face. Fleece has a nap that grabs the jacket lining and looks like outdoor gear the moment the jacket comes off. Smooth knit or felted wool slides under the sleeve and reads as a garment.
• A short collar. The vest collar has to sit below the shirt collar. A tall stand collar shows above the lapel and looks like a jacket liner.
• No logo. The blazer says "I dressed for this." A chest logo says the opposite.
• Length to the belt, not below. If the vest hangs under the jacket hem it looks like a mistake.

Fabrics, ranked for this job

Felted alpaca and merino. Warmest for the weight, so you get a real layer without bulk. Alpaca fibre is stronger than merino, which is why it pills less over a winter of jacket friction, and it is lanolin-free, so it does not itch through a shirt. This is what we make the Rittervest from, which is why I am biased and also why I know it works.

Fine-gauge merino. The classic sweater-vest fabric. Thin, smooth, sits flat. The trade-off is warmth and pilling; a cheap merino zip vest is often done after one season.

Cashmere. Beautiful and warm but fragile under a jacket. Elbows and the zipper line wear first.

Fleece and sweater-fleece. Fine for the commute, wrong under a blazer. It will always look like the office-park uniform.

How to wear it

Dress shirt, vest zipped to a hand's width below the collar, blazer open. Keep the vest and the jacket in different tones so there is a visible layer: charcoal vest under a navy blazer, sandbar or glacier under charcoal or brown. Take the jacket off at your desk and the vest still looks intentional, which is the whole point.

If you want the one we make: the Alpaca Rittervest is alpaca and merino, felted in Peru, with hidden zip pockets and a clean full-zip front, in eight colours, plus a women's cut. Free US shipping and free 30-day U.S. size exchanges.

Returns & exchanges: Start eligible returns and exchanges within 30 days of delivery at returns.ritterwools.com. Eligible U.S. returns and exchanges include a prepaid return label and no restocking fees. No need to email us first. After 30 days, contact help@ritterwools.com for a case-by-case review. Socks and items explicitly marked Final Sale are excluded from standard returns and exchanges. See our return policy for full details.