Preparing the materials for an authentic "buon" fresco

Several months before the the mural wall was constructed my students and I began making lime putty from Hi-Calcium Hydrated Lime (type N) provided fresh from Cheney's Lime in Alabama. Letting the putty age for several months is beneficial and improves its quality in several ways. Our lime will sit for at least six months, however, the longer it ages the better. Many fresco painters insist on using lime putty that is no younger then two years old, and sometimes as much as ten!

Hydrated lime is very inexpensive ($8-9 per 50lb bag) and easily converted into the putty used by plasterers and fresco painters. Those interested in making their own putty, should carefully read the Manufacturer's Safety Data Sheet (MSDS) for Calcium Hydrate (aka powdered calcium hydroxide) and use the proper protective clothing, goggles and gloves.








While waiting for the renovation of Van Meter to be completed the students and I began formal discussions on the technique of buon fresco painting. In addition to learning about the basic materials, they were able to paint on practice tiles to get a feel for painting onto wet (damp really) plaster.

about the "buon" fresco technique

Essentials of the technique: (coming soon!)

A short step-by-step for portable fresco painting:


Portable frescoes can be completed on any rigid surface containing enough texture to hold plaster. In this case I used 3/4" plywood. The black roll is roofing paper used to protect the wood from the wet plaster.


Plaster will not stick to wooden or smooth surfaces so I have fastened expanded metal lath to give it a suitable "grip".


Application of the "scratch coat" mixed from one part lime putty, one part grey portland cement and 2.5 parts of coarse sand aggregate.


"Scratches" are added at the end when the plaster is somewhat firm. Similar to the expanded metal lath, this provides a proper tooth for the subsequent middle layer.


Wetting the dried scratch coat before applying the next layer is needed to keep the top layer's moisture from wicking out to the bottom layer. This prevents cracking and also makes spreading much easier.


This image shows the third and final coat of plaster commonly called the intonaco. It is made up of 3/4 part lime putty to one part fine marbled dust.

Note: The second coat was not photographed but contained a layer made from one part lime putty and two parts medium sized sand. Although only one layer of plaster is needed to paint a fresco (not uncommon) additional layers help increase the strength of the plaster, helping to reduce cracking. Three coats have proven to be stronger then two etc etc.

Before painting begins and as soon as the intonaco is firm enough to withstand impressions from a finger tip, the surface is polished with a clean damp trowel. This helps smooth the plaster if desired and the compression brings lime to the surface.



A finished buon fresco (3'x2') "Michelle Affresco"



A brief history of fresco painting: (coming soon!)

Image and Concept

Coming Soon! Image-making is currently underway. Pending approval of the concept, I hope the mural will incorporate a large hybrid illusion as a major component of the work.

Please check back in the next two weeks to learn more about the image that will be painted in the space as well as the decisions made during its creation.

Coming Soon!

Visit us for week-to-week updates!

Follow our progress as we construct and paint a 300 square foot buon fresco in Western Kentucky University's historic Van Meter Auditorium.

upcoming dates:

February 20th, 9am-?: Installation of waterproofing and expanded metal lath

February 25th-28th (Saturday starting at 9am): Application of a portion of the scratch coat.