Samples are a big hit because they’re a way to test out paper without having to make significant investments with a risk of not liking it. Clairefontaine Triomphe is a personal favorite of mine (that’s no secret), and I’ve put together a sampler pack for sale on GouletPens.com.
Triomphe tablets come available in two different sizes, in both ruled and blank. The A4 size (C6170-blank, and C6174-ruled) is 8.25″x11.75″. The A5 size (C6120-blank, and C6124-ruled) is 5.75″x8.25″. There are two sizes of envelopes as well. The larger size is 8.675″x4.375″ (C9915) and the smaller size is 6.675″x4.5″ (C9966). All of the tablets and envelopes are 90g, and bright white (well, the envelopes are actually just a hiiiint of grey).
I put a sampler pack together to make experimenting with the stationery to be more cost efficient than buying full packs of tablets and envelopes. For $4, you get 4 large sheets (2 blank, 2 ruled) and 2 large envelopes, and 4 small sheets (2 blank, 2 ruled) and 2 small envelopes. Yes, it’s not a TON of paper, but it does allow you to try the entire line of Triomphe to see what best fits your needs for correspondence.