From: owner-scribes@castle.org (scribes digest) To: scribes-digest@castle.org Subject: scribes digest V5 #82 Reply-To: Sender: owner-scribes@castle.org Errors-To: owner-scribes@castle.org Precedence: bulk scribes digest Thursday, March 15 2001 Volume 05 : Number 082 ======================================================================== To unsubscribe from this list, send email to with unsubscribe scribes-digets in the body of the message. Leave the subject line blank. Do not include any additional text. Re: [scribes]: Gesso [scribes]: Re: Gesso [scribes]: 14th cGesso Recipe ---------------------------------------------------------------------- Date: Thu, 15 Mar 2001 03:06:55 +0000 From: Catie Helm-Clark Subject: Re: [scribes]: Gesso Sally Burnell wrote: > > > Could someone please tell me again how to make your own gesso? > > > > I lost alot of my files recently to a computer crash, now I am ready to > get > > back into the swing of things with the making of supplies! > > Greetings, Bianca! > > Here is a recipe for gesso for raised gesso gilding. A more period > recipe would've included lead, but since it's very toxic, this recipe > excludes that ingredient in favour of greater safety: > > 1 T. Calcium Sulfate Dehydrate I'm sorry, but don't you mean calcuim sulfate dihydrate (CaSO4.2(H2O))? If you start with completely anhydrous CaSO4 or with partially-dehydrated calcium sulfate hemihydrate (better known as plaster of paris), you will get set-up solid plaster ( CaSO4.2(H2O) ) as a result, unless you are slaking the plaster or anhydrous CaSO4 from the get go (slaking = mixing up the plaster of paris with floods of water to prevent it from setting-up, because each CaSO4 unit will be surrounded by so many water molecules that it will rarely "see" any other CaSO4 units to bond with) Looking at your recipe, I would think that the anhydrous CaSO4 could screw up your formulation due to setting-up (hydrating) of hard plaster chunks. Maybe the mixing with the bole is the preventative of making hard plaster chunks The hydration of the meta-stable dehydrated calcium sulfate minerals (oops, make that compounds... hi, Bryon) is exothermic and almost always runs until all the dehydrated components are converted to the stable CaSO4.2(H2O) state. The reactions are exothermally too, which is why plaster casts give off heat as they harden. I have always slaked my plaster first, following Ceninni's instructions. It has always worked fine for me. The only drawback is that it takes many days to do it properly. Slaking the plaster properly converts the dehydrated CaSO4 minerals into unclumped CaSO4.2(H2O), which is also one of the two compounds used singly or in combination to make whitewash. And it comes out of the bucket finer than flour - really cool stuff! Slicker in feel than talc! The physics nerd in me, who is always looking for workable shortcuts, is saying that 45 minutes in a mortar is silly when five minutes shaking in a 1 gallon ziplock should do the trick... how about 2 minutes in a heat resistent container in the dryer? no? what do you mean you don't want dents in your dryer??? I've never had bubbles in my gesso. Now I'm trying to figure out why your recipe might produce bubbles... Any thoughts on this, Bryan, oh fellow chemistry nerd? (Could the sugars in the honey be possibly fermenting? nah - too far fetched... Well, the organic chem nerd I'm married to might know. He'll be up for the weekend, so I'll ask) Bubbles in the gesso... hmmm... this is going to drive me nuts... Zinc or titanium white also work in substituting for the original lead white. I've used sugar successfully as a substitute for the honey. You know, if I'm in a time crunch, I have been known to resort to Elmer's glue. Kathleen (Katherine?) Allen, a laurel from the Middle long ago in the mists if time, came up with this trick, if I remember correctly. You paint the Elmer's just like you would with the gesso. Then you hydrate it with your breath through a thin tube to lay your leaf, just like gesso. One of the best shortcuts I know! Wish I had thought of it! A very clever lady she was... ttfn, Therasia ___________________________________________ Reward doubled in Abernathy murder case http://www.onewest.net/~no1home/index.html =================================================================== To unsubscribe from this list, send email to with a blank Subject: line and unsubscribe scribes in the body of the message. Do not include any additional text in the body. ------------------------------ Date: Thu, 15 Mar 2001 09:34:04 EST From: RenScribe@aol.com Subject: [scribes]: Re: Gesso The handout I use for all of my gilding classes is online at http://www.geocities.com/Athens/Forum/2963/gilding.html If someone doesn't have web browsing capabilities, let me know and I'll be happy to send a copy either e-mail or snail mail. Both of these books have recipes... as well as instruction: _Secreta: Three Methods of Laying Gold Leaf_ by Joyce Grafe _The Technique of Raised Gilding_ by Jerry Tresser Best of Luck :-) Eibhlin =================================================================== To unsubscribe from this list, send email to with a blank Subject: line and unsubscribe scribes in the body of the message. Do not include any additional text in the body. ------------------------------ Date: Thu, 15 Mar 2001 10:36:14 -0500 From: Randy Asplund Subject: [scribes]: 14th cGesso Recipe Hey gang, For a recipe based on a 14th c. Italian gilding seat recipe check out the Unofficial MK Scribes' Handbook, downloadable from my website at http://www.provide.net/~randyaf There's no lead in it. Obviously, if you are going to use plaster, it MUST be slaked. Otherwise it will solidify and any bole you put in there will just get trapped into the matrix of the slid chunk. My understanding is that the bole and lead serve the same function. They are a soft particle which improves the smoothness of the burnish. If you use lead, then yo don't need the bole, but the bole is still present in a small amount to give color against the white pigment. If you have a high percentage of bole, you need no white lead. RanthulfR Catie Helm-Clark wrote: > > Sally Burnell wrote: > > > > > Could someone please tell me again how to make your own gesso? > > > > > > I lost alot of my files recently to a computer crash, now I am ready to > > get > > > back into the swing of things with the making of supplies! > > > > Greetings, Bianca! > > > > Here is a recipe for gesso for raised gesso gilding. A more period > > recipe would've included lead, but since it's very toxic, this recipe > > excludes that ingredient in favour of greater safety: > > > > 1 T. Calcium Sulfate Dehydrate > > I'm sorry, but don't you mean calcuim sulfate dihydrate (CaSO4.2(H2O))? > > If you start with completely anhydrous CaSO4 or with partially-dehydrated > calcium sulfate hemihydrate (better known as plaster of paris), you will > get set-up solid plaster ( CaSO4.2(H2O) ) as a result, unless you are > slaking the plaster or anhydrous CaSO4 from the get go (slaking = mixing up > the plaster of paris with floods of water to prevent it from setting-up, > because each CaSO4 unit will be surrounded by so many water molecules > that it will rarely "see" any other CaSO4 units to bond with) > > Looking at your recipe, I would think that the anhydrous CaSO4 > could screw up your formulation due to setting-up (hydrating) > of hard plaster chunks. Maybe the mixing with the bole is the > preventative of making hard plaster chunks > > The hydration of the meta-stable dehydrated calcium sulfate minerals > (oops, make that compounds... hi, Bryon) is exothermic and almost > always runs until all the dehydrated components are converted to the > stable CaSO4.2(H2O) state. The reactions are exothermally too, which > is why plaster casts give off heat as they harden. > > I have always slaked my plaster first, following Ceninni's > instructions. It has always worked fine for me. The only drawback is > that it takes many days to do it properly. Slaking the plaster > properly converts the dehydrated CaSO4 minerals into unclumped > CaSO4.2(H2O), which is also one of the two compounds used singly > or in combination to make whitewash. And it comes out of the bucket > finer than flour - really cool stuff! Slicker in feel than talc! > > The physics nerd in me, who is always looking for workable shortcuts, > is saying that 45 minutes in a mortar is silly when five minutes > shaking in a 1 gallon ziplock should do the trick... how about 2 > minutes in a heat resistent container in the dryer? no? what do > you mean you don't want dents in your dryer??? > > I've never had bubbles in my gesso. Now I'm trying to figure out > why your recipe might produce bubbles... Any thoughts on this, Bryan, > oh fellow chemistry nerd? (Could the sugars in the honey be possibly > fermenting? nah - too far fetched... Well, the organic chem nerd > I'm married to might know. He'll be up for the weekend, so I'll ask) > Bubbles in the gesso... hmmm... this is going to drive me nuts... > > Zinc or titanium white also work in substituting for the original > lead white. I've used sugar successfully as a substitute for > the honey. > > You know, if I'm in a time crunch, I have been known to resort to > Elmer's glue. Kathleen (Katherine?) Allen, a laurel from the Middle > long ago in the mists if time, came up with this trick, if I remember > correctly. You paint the Elmer's just like you would with the > gesso. Then you hydrate it with your breath through a thin tube to > lay your leaf, just like gesso. One of the best shortcuts > I know! Wish I had thought of it! A very clever lady she was... > > ttfn, Therasia > ___________________________________________ > Reward doubled in Abernathy murder case > http://www.onewest.net/~no1home/index.html > =================================================================== > To unsubscribe from this list, send email to > with a blank Subject: line and > unsubscribe scribes > in the body of the message. Do not include any additional text in > the body. - -- Randy Asplund (734) 663-0954 Science Fiction and Fantasy Illustration 2101 S. Circle Dr., Ann Arbor, MI. 48103 See a Universe of art ranging from Medieval Manuscripts to Star Trek and Magic: The Gathering at: http://www.provide.net/~randyaf =================================================================== To unsubscribe from this list, send email to with a blank Subject: line and unsubscribe scribes in the body of the message. Do not include any additional text in the body. ------------------------------ End of scribes digest V5 #82 ****************************