Ok, I have a medium/heavy weigth blanket for Duke for when it's really cold out. But I would like to get light weight one for this time of year when the weather is in the 30's-40's, so he doesnt get so wooly mamouth on me.  (he's so hard to get dry after a good workout).  So my question is, what is a good denier weight for 30's-40's? or just a sheet? 

The denier has to do with the weave density and the "toughness" of the fabric.  For all turnouts, IMHO, you want not less that 1200 denier (the higher the # the better), ripstop, and waterproof, usually nylon  The thermal weight of light, medium, and heavy is an indicator of how warm the blanket is.

Ditto what Poverty says on the denier - though I have a 600 denier turnout by Weatherbeeta that has held up very well. As far as him wooly mammothing on you - the only thing that will keep him from doing that is putting him under lights. The blankets won't keep him from getting hairy - it's the length of sunlight during the day (or lack thereof) that creates the hair. 

And ditto Ropin', on the fuzz factor.  The ONLY other alternative I know of to extended light time is one of the various, frequently hilarious-looking, clips - they do work quite well though.  With anything that takes the natural winter coat away, you will need to blanket more heavily to compensate.

Hubby's pony is a shaggy Yak... and his team roping buddies gave him some really weird looks when he showed up one winter with a trace clip. Sure made cooling his horse out easier - since we don't have a barn and stalls, and often got home from roping practice after 10pm a trace clip and jammies was the way to go to keep his horse healthy!

DukesMom:

Ok, I have a medium/heavy weigth blanket for Duke for when it's really cold out. But I would like to get light weight one for this time of year when the weather is in the 30's-40's, so he doesnt get so wooly mamouth on me.  (he's so hard to get dry after a good workout).  So my question is, what is a good denier weight for 30's-40's? or just a sheet? 

OK, the "denier" # is the # of threads in one square inch.  Therefore, the higher the number the tighter the weave.  Meaning it's more waterproof.  Now, as for blankets that say "ripstop" that just means that with the higher # denier the tighter the weave the harder it is to fray.  BUT it will. 

In your situation what I would do is to buy a blanket that says something along the lines of "wicks away moisture".  When you are done riding even if he's still wet, cooled (internally) but still wet.  Pull his tack and throw his blanket on.  I"ve been doing that for years and have (knock on wood) never had a horse get sick.  I have one mare that is a very heavy sweater and even in the coldest winters she'll sweat bad.  I get back from riding and as long as she's not breathing hard and really worked up I pull her saddle, put her blanket on and kick her out.  (I have a run in shed, no barn with stalls).  My horses have always (knock on wood again, lol) been healthy.

I have always found it's better to blanket them right away and let their bodies cool slower with a moisture wicking blanket on then to try to walk them till they are dry. 

A slight disagreement - a blanket that says waterproof (at least the good ones) have had a waterproofing material applied, just like on a good raincoat. After several washings/seasons it may need to be reapplied.  And ripstop is a feature (don't know if it still is, but it used to be patented) that is built in to the material.  I have seen very loose contructions that had ripstop.  I have no idea how it works, but it will keep the original tear from increasing unless more force is applied.

Probably your best bet would be to get a fleece wicking sheet and put a lightweight turnout over it, especially if you want to turn your horse out.  The turnouts are also breathable so the wicking would carry up through the blanket and out, while cutting any nasty wind or weather.

But I'm a huge worrier, so I get a lot of grief for "spoiling" my guys! LOL

 Do you all feel that fleece is a better cooler than wool? I have a wool cooler sheet that I use with a waterproof, breathable, LW turnout. I like the wool but have never tried fleece.

Wool is actually the best of all.  B/c of its natural source, it retains warmth even while wet and moves the moisture away from the body.  Fleece is more common b/c it is less expensive (usually).  By all means use wool since you have it.

ripstop does just what it says...if the blanket gets hole torn in it, it keeps it from getting bigger.  It has nothing to do with being waterproof.  The 1200 denier nylon I believe is one of the toughest materials you can get in a turnout these days.  If you have a horse, or pasture mates that are really tough on their blankies...this is the best to get.  They really really have to try to rip it.  My boy has a 1200 denier Amigo turnout and so far...no rips and his pasture mates have always been rough on his turnouts.  I've had to buy him a new one every year, so this year I decided to spend the extra money and get him the Amigo (Rambo's are ever better, same company).  We'll see how long this one lasts.  I suspect he will have it for a long time.