the last few years we’ve received countless calls from customers wanting
to understand the conflicting information they’ve read or been told
on whether hardboard (most often referred to as masonite) is a good substrate
for painting. In the following paragraphs we’ve condensed some of
our research and information regarding the choices we’ve made for
the hardboard we use to make our wood panels. For those artists who have
been reluctant to use the current generation of hardboard, this up to date
information should provide a level of comfort to try this versatile and
long-lasting substrate that has gained a wider following as a result of
today’s revival in panel painting.
the bad rap on “masonite”?
begin, the word “Masonite” is a brand name for “hardboard”.
It has been commonly known as “masonite” after the founder of
the Masonite Corporation, William Mason invented this wood product in 1924.
Today a few select manufacturers in the US as well as foreign companies
produce hardboard. Since Ralph Mayer wrote The Artist’s Handbook in
1949 where he warns against using “masonite”, the method of
manufacturing hardboard has changed. This book, already in its 5th revision
has not updated artists on the current generation of US made hardboard.
Thus the incorrect information continues to be disseminated in both classroom
the 40’s and 50’s, tempered hardboard was made by immersing
the panels in dipping tanks of tung or linseed oil to harden them, leaving
an oily residue that caused adhesion problems for artists. Untempered boards
also had problems with chipping and fraying, which made conservators leery
of paintings done on these now outdated hardboards. Over 20 years ago, the
high cost of tung and linseed oil forced U.S. manufacturers to change the
way they manufacture hardboard. Today’s U.S. hardboard is made differently
and does not have the characteristics of the old hardboard.
what is the difference between tempered and untempered?
Gottsegen, in his book, A Manual of Painting Materials and Painting Techniques,
writes that both tempered and untempered hardboard can be used successfully
for painting. Both untempered (or standard) and tempered hardboards are
made by the same process. The only difference is that there is one final
step for some tempered hardboard. A very small amount of oil (normally linseed)
is applied with a roll coater and then baked. We have found manufacturers
applying as little as 1.8 oz (approximately 2 tsp per side) on a 4 x 8 ft
of this oil is flashed off when the boards are baked at temperatures about
400 degrees F. This oil “tempering” is invisible and does not
leave an oil residue on the panel that can cause adhesion problems, as did
the outdated hardboard. The purpose of this process is to make the board
stronger and less prone to warping. Unfortunately, artists and conservators
have incorrectly been led to believe that even today’s tempered hardboard
is impregnated with a lot of harmful oil.
Manufacturing Process Explained
have found that how the hardboard is manufactured and which species of wood
is utilized, are more important questions for the artist than whether or
not it is tempered. Three methods of manufacturing hardboard are used: 1)
Wet Process, 2) Wet/Dry Process, and 3) Dry Process. In Wet Process after
the wood chips are pulverized into wood fibers, they sit in water and are
aligned in such a way that an internal bond is created using the natural
resins already in the wood. This process produces the S1S (smooth one side)
with a screen pattern on the back.
Wet/Dry Process is essentially the same as the wet process except that a
dryer is used to remove part of the water from the fibers so that the board
can be pressed between two plates to create the S2S (smooth 2 side). Dry
Process hardboards in comparison are manufactured without water by taking
the pulverized wood chips and adding different synthetic additives to bind
the fibers together and press them to make both S1S and S2S. The various
methods can produce different quality hardboards depending on the species
of wood, additives, and techniques used in manufacturing.
How We Decided On Our Hardboard
extensive research and testing, we chose hardboard that is made through
the Wet/Dry method. The Wet/Dry process method removes the lamella that
contains many of the lignins and tannins that can cause discoloration in
a painting over time. Through the use of water, this process leaches out
many of water-soluble chemicals and acids that exist in the wood, leaving
a more inert surface than a solid wood panel. No additional additives are
necessary in this process because the natural wood fibers are used for binding,
resulting in a stronger, more uniform, and denser board.
The next step in choosing our hardboard was to determine
which species of wood to use. For example, hardboards manufactured through
the dry process such as MDF boards are made from softwoods that tend to
be more acidic in content. The Ampersand Hardbord™ is primarily
manufactured from Aspen trees that have more uniform fibers and have more
of a neutral pH than that of other woods.
for the tempered/untempered question…In all of our testing using both
untempered and tempered hardboard, we find that today’s tempered hardboard
does not cause adhesion problems. In fact, our tempered hardboard seals
more effectively with our primers than the untempered. Ampersand’s
manufacturer of its 1/8” tempered hardboard uses less than 1.8 oz
(2 tsp per size) of a pH neutral vegetable oil on a 4ft x 8ft sheet. After
baking, there exists less than .03 oz per square foot of oil on the surface.
When artists call Ampersand we always recommend using tempered hardboard
because it will resist warping and the edges won’t fray as they sometimes
do with untempered or standard hardboard. Furthermore, tempered hardboard
creates a better seal with oil and acrylic primers so that the painted surface
is protected from any potential discoloration.
is wood – so seal it!
wood surfaces should be sealed with a good primer before gessoing or painting
on them. Unlike hardboard that has been processed and reconstructed, plywood
and other solid wood panels still have their cell structure intact and the
harmful lignins and wood tannins could affect a painting if not sealed correctly.
Ampersand recommends using Golden’s Acrylic GAC 100 to seal panels
for water-based painting and the Gamblin's Oil Painting Ground for use with
oil paints. Ampersand’s Hardbord™ can be primed using these
products or try one of the already sealed and coated panels.
Ampersand uses a two part emulsion process for sealing
the hardboard before applying our different acid-free grounds. We first
apply an acrylic sealer that seeps into the fibers of the hardboard and
then we do a final sealing layer to create a barrier between the wood
and the ground.
barrier will ensure that over time the lignans in the hardbord will not
interact with the ground or your paints. Each of our grounds whether it
be the acrylic gesso on Gessobord or our clay-coated grounds for Claybord
smooth, Textured Claybord, and Pastelbord are non-yellowing and have been
created to give the artist a variety of surface options to choose from.
These grounds are carefully "poured on" to the surface and dried
to ensure excellent adhesion with the sealing layer.
process along with our acid-free coatings gives artists painting on Ampersand’s
wood panels the assurance that their work will be around for a long time.
We realize that in these short paragraphs we couldn’t cover everything,
so please give us a call if you have any further questions – 1-800-822-1939.
physical properties of any hardboard are primarily dependent upon the wood
furnished, the degree and uniformity of defiberation, the ability to properly
form the wet mat at economical production speeds, the density to which the
mat can be consolidated in the hot press and the degree of heat treatment
after consolidation. Manufacturers have a varying degree of choice with
respect to finished properties, depending upon their physical location and
Ampersand’s source for hardboard holds a prominent
position in the hardboard industry. A number of wood species are available,
making it possible to select the species according to specific property
requirements of the end product. Slow-growth aspen produces clean, strong,
highly-uniform fibers for our S2S hardboard. A fine fiber slush overlay
provides S2S with an extra smooth surface for finishing. By fusing special
additives into the cellulosic structure, they have developed a high water
resistant board while maintaining the high quality finishing properties.
aggressive manufacturing control systems and frequent QC testing, assure
the qualities of flatness, dimensional stability, machinability, smoothness,
and paint hold-out. The hardboard we use is highly engineered S2S(smooth
two sides). The manufacturing process begins with slow-growth aspen that
produces clean, highly uniform fibers making the S2S a dimensionally stable
and consistently flatter board. The unique fiber slush overlay provides
a superior smooth surface that leaves no ripples, dimples, or blemishes.
This smoother surface is impeccable for wet or dry finishing applications,
giving us a superior finished quality product. The following information
compares Ampersand’s Hardbord to the standard hardboard on the market:
Hardboard S2S 1/8?
Standard Untempered S2S 1/8?
of Rupture, psi
Safe and Superior Quality
hardboard supplier does not use urea-formaldehyde glue in the manufacturing
process. They rely on the natural lignin in wood for the bonding of the
wood fibers, making our board environmentally sound. Ampersand’s Hardbord
is considered HWR hardboard (High Water Resistant) and is suitable for those
applications where improved water resistance is required over normal hardboard.
Special additives are fused into cellulosic structure to form a barrier
against water absorption. This results in improved dimensional stability,
so the products you make with HWR hardboard are far less likely to swell
or warp. Aggressive manufacturing control systems and frequent quality control
testing insure consistent results. These improved properties are achieved
while maintaining the industry’s leading finishing qualities expected
for the hardboard we use.