There are many different manners of working with soft/dry pastels. I’m using a method that involves a lot of layering and juxtaposing of colours, which puts some demands on the papers I use.

Papers need to:
have a distinct but fine grain that “grabs hold of” the pastel pigments
continue to hold onto the pigment dust
allow for many layers
be light or white
be archival or acid free
be easy enough to cut to desired size

Here I give you my personal experience with different types of paper. I want to stress that it is indeed personal, and that other artists may have different views. I’m judging the papers based on how I work. All papers mentioned below are made for the serious amateur and the professional pastellist. There exist many more pastel papers, especially from the USA, but I have not tried these.

Plain papers

Canson Mi-Teintes, diverse Ingres, Fabriano’s Tiziano, and similar, EuropeanTexture: Usually they are smoothish or rough with clear texture, often more textured on one side, and less on the other. I prefer the less textured, as I want the painting to “speak”, not the paper.
Colour: Comes in many colours that may fade with time. Not an issue when using white and light papers.
Grabability: Surprisingly good, for a maximum of 5 layers of harder pastels like Rembrandt and ArtSpectrum. Will take two additional layers of supersoft pastels like Schmincke. Dust stays put, basically, even without fixative.
Cutability: Very easy to cut.
Longevity: Buffered or acid free, they last for a long time. (Note: Canson MT black is not acid free, and will fade.)

Used by me for: Sketches, tests, works with softer pastels like Unisons, and work that doesn’t need to be layered much.
Not suitable for water soluble primers or underpainting techniques.

Primed papers or card

There are two basic kinds of primed papers I use: Primed with “gritty stuff” mixed into the primer, and primed and gritty stuff strewn over the primer. “Gritty stuff” is usually some sand, ground pumice, ground marble, or similar minerals, with two exceptions. 

ArtSpectrum’s Colourfix primer, and Colourfix paper, Australia
Texture: Readymade papers have a fine ‘pitted’ texture, from the screen-print method of applying the primer to watercolour paper. Can be soaked in tub and pastel washed off, many times. Reusable.
Colour: Comes in many colours, including white, natural, and Australian grey
Grabability: Good. After several layers, a certain plowing effect appears when a pastel stick dislocates what is already on the paper, which works as a type of automatic blending. Unfixed paintings do drop dust, but very little.
Cutablilty: Easy, a bit hard on knife-blades.
Longevity: Many years. Acid free.

Used by me for: Painting, plein air, sketching, testing, experimenting – it is the all-round paper. Takes watercolour underpaintings.

The Colourfix primer: Can be applied to almost any dry and non-greasy surface according to the manufacturer. Prime any paper or canvas that will take a water-soluble primer, and you can paint with pastels on it. As the primer comes in many colours, they can also be used as an underpainting. Transparent primer can be applied over a watercolour painting.

Papers with grit on top

LaCarte, from Sennelier, France
Texture: Fine grit made of vegetable matter and cork. Mixed large and small particles make for uneven deposits of pastel pigment, which I find attractive. Parts of the grit tends to get loosened by the pastel sticks, but is tolerable (by me). Fingerblending works great, you keep your fingerprints intact as the grit is soft.
Colour: Many, including creamy whites
Grabability: Very good. After several layers the plowing effect may appear.
Cutablilty: Easy enough, for card.
Longevity: Many years. However, the glue holding the grit will dissolve with moisture, so a good sneeze can ruin the paper even before you start to paint, and during, and after. Finished framed paintings behind glass should have no problems.

Used by me: Seldom, even though it is good enough, but not a favourite.

 
Velour, many makers
Texture: Soft fibers glued to paper. So irregular it looks very even. Fibers have a ‘spring’ to them, so a fair amount of the finest pigment dust gets thrown up in the air, a handbreadth or two, and hovers there for a long time. No blending, the fibers keep the dust in place. Layering blends a bit.
Colour: Comes in light and white colours too.
Grabability: Fine for harder pastels. Soft pastels fall off, continuously, and in an avalanche if you smack the paper on the back.
Cutablilty: Very easy to cut.
Longevity: Many years.

Used by me for: Experiments, very rarely, as it throws dust into the air. Will not get any more of it, as I use pastel sticks with cadmium in them and avoid breathing in dust. The fact that it doesn’t hold on to pigment very well disqualifies it.

 
Sansfix, by Schmincke, Germany
Texture: Irregular grit, but with a pebbly texture. The particles are relatively large and feel smooth, so finger blending is kind to fingertips. Pastel dust can be washed off in shower. Reusable.
Colour: Several, including light and white.
Grabability: Surprisingly mediocre with harder pastels. Plowing starts early. Back-smacks dislocate pigment in larger amounts than I care for, also after using 3 light coats of fixative.
Cutablilty: Relatively easy, but hard on blades.
Longevity: Many years.

Used by me for: Experiments. Not a favourite. And only until I run out of my stock. Will take wet underpaintings.

Wallis professional, USA
Texture: Even (some batches uneven) sharp grit. Feels like sandpaper – is a sandpaper, of artist quality. Takes up to 25 layers. Eats pastels. First layer not blendable as it will not move. Successive layers blendable, preferably with protected fingertips, or with some implement, as packing peanuts, pieces of pipe insulation. Reported to not take rubbing alcohol for underpainting, as it becomes ‘gummy’. Watermedia is to be used only in upright position, and never soak it. (Museum quality is said to be washable.) Reusable many times if dust is brushed off. (Can be vacuumed off, too, with some care.)
Colour: white and a medium dark neutral brown-gray.
Grabability: Excellent! Dust stays put. Very little plowing, after many layers.
Cutablilty: Takes some effort, as the Professional is on card (Wallis Museum is on rag). Very hard on blades, one cut ruins the edge of blade.
Longevity: Manufacturer promises 500 years. Will probably last longer.

Used by me for: Anything! A favourite!

Fisher 400, England
Texture: Sharp fine even grit, on card. Artist’s quality sandpaper. Eats pastels, so it is a good idea to start with the harder and cheaper ones. First layer not blendable, stays put. Successive layers blendable, preferably with protected fingertips, or with some implement. Fingerblendable when grit is cushioned by pigment layers. Takes waterbased media as underpainting, and resumes shape after drying without stretching. Rubbing alcohol works well, also to sink dust into grain to allow for even more layers (hardly necessary).
Colour: Medium beige, can be tinted.
Grabability: Excellent! Almost no plowing. Very little fall off when smacked on back.
Cutablilty: Takes some effort, as it is on card. Very hard on blades, one cut ruins blade.
Longevity: Manufacturer gives no time, but as it is acid free, it should last very long.

Used by me for: Anything! A favourite!
I certainly and warmly recommend it to Europeans as equal to Wallis Professional,  and cheaper to get within the European Union. (No extra taxes or duties.)  Jackson’s ship it to most European countries. See Tim Fisher’s homepage for more info on his paper.