Guys,
All Butyrate dope shrinks.  Non tautening just shrinks less.  Can't remember what the % is but if Bill Byles comes on he can probably give the numbers.  Sig has or had two kinds of clear dope in their line.  Supercoat and Litecoat.  Supercoat was a tautening dope and Litecoat was a non tautening.  All colors of Sig dope were made using a non tautening formulae.  Brodak makes both clears and colors with a non tautening formulae.  Brodak dope has more pigment in the colors so you get better coverage than with Sig dope.  When using Sig dope I used to add raw pigment to improve coverage especially of white and yellow.  I believe that Brodak adds additional plasticiser to their dope to make it more flexable.  Randolph dope is high on pigment content also and coverage is very good.  The only problem with Randolph is that quarts are the smallest quantity you can buy.  Some modellers can't see spending say $25 for dope when they only need 4 oz for some trim on their next world beater.
Alan Resinger

Hi Alan,

I just saw this post and your comment he "All Butyrate dope shrinks.  Non tautening just shrinks less.  Can't remember what the % is but if Bill Byles comes on he can probably give the numbers" is right on.  Tautening type butyrate shrinks about 10% to 12%; "non-tautening" type shrinks about 5% initially then as the plasticizer leaches out and sublimes the dope film begins to shrink more and become more brittle.  However, this is normally more of a problem on full-scale airplanes rather on our models since the cover on a full-scale airplane can be on the airframe for 20 or more years and often sitting outside exposed to weather.

Just for further trivia that is more info than needed: nitrate dope tends to shrink slightly more in terms of percentage of shrinkage than does butyrate, however nitrate has a somewhat lower tensile strength than butyrate in the dry film. 

Wayne,

No it wasn't a Grumman Albatros.  It was a WW1 Albatros, 1/3 scale.  It finally arrived from MAN.  I really wanted to look for it before we left for Fl. just to see what it looked like.

We are now firmly enconsed in Florida.  It appears as though we brought the cold weather with us.  The weather guys are talking freezing to 20s tonight.  Remember, we're in south Florida, not north!

At least I forgot to bring the plans for the B-25 when we left.  Therefore, I can't start building that while we're here.  Didn't quite have time to finish the Twisters.  Just need to final sand and buff out one and clear coat, sand and buff out the other.  And, of course, I forgot a bunch of stuff, not that the mini van wasn't full.  We almost have stuff put away to the point I can start doing stuff besides taking extra Alleve and laying down trying to get rid of major pain.

Talk to ya later,

Bob