I wrote this guide for the customers at VeneerSupplies.com who have sent me so many excellent questions over the years about this type of veneer. It certainly has many uses in all kind of projects and its popularity is always growing. There are several types of backings that can be applied to a veneer but the most common are paper and wood (paperbacked veneer and 2-ply veneer). The questions and answers below should give you a solid foundation to begin any project with this type of material. Feel free to email me any other questions. I'll reply to your message and post the answers here.
Paperbacked veneer is a real wood veneer permanently bonded to a paper backing. This backing is applied to keep intact the individual wood veneers used to make up the full width of the sheet. A four foot wide paperbacked veneer consists of multiple veneers glued together side by side. The backing also minimizes seasonal expansion and contraction of the wood caused by changes in ambient humidity.
The paper backing is generally available in a 10 and a 20 mil thickness. "Mil" or mil thickness is the common measurement of a coating. One mil equals 1/1000 of an inch. A quarter inch would be 250 mils. The backing is not removable.
A 10 mil backing is best for most projects. However, a 20 mil version is available for situations where the substrate is less than perfectly flat. In this case, the extra paper thickness allows the veneer maintain a more consistent look after application. Keep in mind that the 10 and 20 mil thickness is a reference to the thickness of the paper backing, not the veneer face.
Wood-on-wood, also known as "2-ply veneer" is two wood veneers permanently bonded together. The face veneer grain is perpendicular to the backer veneer which provides protection against bubbling which occurs when a veneer is improperly bonded to the substrate. This type of "crossband construction" allows the veneer to bend on moderate curves in the horizontal or vertical direction. The veneer used on the back side of a 2-ply veneer is often an imported hardwood of lesser value.
Pressure sensitive adhesive (PSA) veneer is a type of paperbacked veneer that is a simple and easy alternative for applying veneer without the need for a liquid adhesive. Utilizing 3M™ adhesives, PSA veneer provides a permanent bond to any smooth substrate that is dry and free of dust and contaminants. PSA-backed veneer is the perfect choice for cabinet refacing, hi-fi speaker building, automotive dashboards and much more. It can be cut and trimmed with ordinary tools, such as scissors or a razor knife.
Keep in mind that PSA backed veneer is strong stuff and once it is applied, it can not be repositioned. More information about applying a PSA veneer can be found further in this article.
VeneerSupplies.com is the companion website to the JoeWoodworker pages. You'll find over 5,000 veneer related products there. If you are looking specifically for paperbacked veneers, check out this page. Wood-on-wood or 2-ply veneers can be found here.
Wood-on-Wood or 2-Ply Veneer - .035" or just over 1/32"
All thicknesses may vary by .005 inch. These dimensions are based on the veneer and edgebanding offered at VeneerSupplies.com.
Generally speaking, the actual wood part of a paperbacked veneer is .015" but the thickness can vary based on the amount of finish sanding done at the factory. The factory sands each veneer sheet until it is perfectly smooth.
A 10 mil backed veneer is used when the substrate is smooth and flat. Some cabinetmakers will only use 10 mil veneer on vertical surfaces and 20 mil on horizontal parts such as desk and table tops.
Regardless of the substrate position, a 20 mil backed veneer or 2 ply veneer should be used if the substrate is not smooth since the thicker backer will help hide some substrate imperfections. Additionally, a 20 mil veneer is often used on curved projects.
Keep in mind that the wood veneer face is the same thickness regardless of the backer. The 10 or 20 mil specification refers only to the thickness of the paper backing.
The standard size for most backed veneer is 4' x 8'. The 4 foot measurement is the width of the sheet across the grain. The 8 foot measurement is the length of the sheet parallel to the grain. Most vendors oversize the sheets by ¼" on both the length and the width.
VeneerSupplies.com has a sample book containing 41 samples of backed veneer. The book contains samples of ash, bamboo, birch, cherry, fir, hickory, lacewood, mahogany, maple, red oak, white oak, pine, rosewood, sapele, teak, walnut, wenge, and zebrawood. Samples of PSA, 2-ply, 10 mil and 20 mil veneers are also included. Click here for more information.
The part of the project that the veneer is applied to is called the substrate. Here is a list of substrates and adhesive information. Keep in mind that the substrate must be smooth, clean, dry, and acclimatized prior to application of the veneer. Note that this chart applies to paperbacked veneers only.
More information about various veneering adhesives can be found here.
2 - With adequate ventilation or a NIOSH approved respirator, melamine and plastic surfaces must be heavily sanded with 80 paper and wiped with a tack cloth. The surface must then be cleaned with denatured alcohol. The veneer should be applied within 45 minutes of cleaning and permanently "seated" using a veneer scraper.
3 - VeneerSupplies.com does not recommend application of paperbacked veneer directly to drywall. Instead, we recommend covering the drywall with ½" MDF using construction adhesive. The veneer can then be applied to the MDF.
4 - It is always a good idea to coat MDF with shellac first and sand it lightly when dry. Then apply the PSA veneer.
5 - Seasonal humidity changes can allow particle board can expand and contract more than some other substrates. This is only problem if there is concern about "creeping" of the veneer. This movementlly is most prevalent on flat cut wood veneers (particularly maple). To minimize creeping issues, use MDF instead of particle board and consider using a hard setting adhesive.
Paperbacked veneer can be used with projects that will be exposed to weather. However, we have found that epoxy is the only adhesive that will withstand the outdoor environment.
Allow the veneer and substrate to acclimate in the same work area for 48 hours. This will ensure that the moisture content in the veneer and substrate has equalized.
Begin the acclimation process by unrolling the veneer and laying it flat. The ideal shop environment is relative humidity of 35% and a temperature of 70° to 80°F. It may be necessary to place weights on the ends of the veneer to keep it flat while it acclimates and losses its "rolled memory".
One of the most overlooked aspects in contact cement veneering is adhesive coverage, yet it is the single most important part of this veneering method. It is critical that all areas of the veneer and substrate are coated with adhesive. Any areas left dry may result in the veneer bubbling after application. For solvent-based contact cement, it is a good idea to apply two coats (per side) with a glue roller. Water-based contact cement generally requires only one coat per side.
If you are using contact cement you'll only need a veneer scraper to apply the veneer. More information about the veneer scraper can be found on this page. A handheld roller is not suitable for applying veneer. It simply does not concentrate enough pressure over the contact surface to create a durable bond. A veneer scraper is a must! Be sure to scrape the entire veneer surface (scraping with the grain) to achieve a maximum strength bond. Most manufacturers recommend scraping the surface twice. Always use the centerline technique (figure 2) when using the scraper tool.
Keep in mind that PSA adhesives bond instantly on contact. Be certain that you have the veneer positioned correctly before applying the veneer. After the veneer has been scraped down, no additional clamping is necessary.
Iron-On Veneering with Heat Lock™ Glue
No. Each sheet is made up of several veneers, called faces, laid side by side with opposite sides showing. This is called bookmatching. The individual veneers used to make sheet of backed veneer can range from 3" to 8" in width. With the exception of burls, the face veneers are 8 foot in length on a 4' x 8' sheet.
The veneers used to make a 4 x 8 sheet are laid up in the sequence from which they were sliced from the tree. This creates a visually pleasing result. If you look close enough you might be able to see the joint line because of the visual effect of the matching grain on the adjacent veneer on the sheet. The quality of the seam between each veneer is what defines the visibility of the joint. VeneerSupplies.com sells a higher grade of veneer in which joint issues simply do not occur. You will never see a gap or filler in the joint.
If you are using contact cement or PSA to bond the veneer to the substrate, it is likely that the joint will either open up or bind-and-rupture. Use a hard setting adhesive such as Ultra-Cat or Better Bond Cold Presss veneer glue instead. These adhesives will require a means of clamping the entire veneer surface while the glue sets up. A vacuum press is the ideal means of doing this.
After the veneer has been stained and finished, the backer is barely visible on most species. Below is a picture of my desktop with a paper-backed cherry veneer used on top and a cherry hardwood edge. The line between the backing and the face veneer is almost impossible to see.
The 4 foot measurement is the cross-grain width and the 8 foot measurement is the long grain length.
When veneer is sliced, a distortion of the grain occurs. The knife blade, as it hits the wood, creates a "loose" side where the cells have been opened up by the blade and a "tight" side. Because the "tight" and "loose" faces alternate in adjacent pieces of veneer in book matching, they may accept stain differently. This may result in a noticeable color variation called barber poling. Slip matching (all veneer faces are in the same direction) is often used in quartersawn and rift cut veneer to minimize the barber pole effect. This is an available option at VeneerSupplies.com.
Super-Soft Veneer Softener can be lightly applied to paperbacked veneer. The preferred method is to dampen a soft cloth or paper towel with softener and pad it on to the veneer in light, overlapping motion. It is not a good idea to saturate the veneer to the point at which the backing is wet. Since the face (the wood part) of the paperback veneer is very thin, a light coat of softener is all that is needed to give the veneer the extra flexibility that is sometimes needed on tight curves.
You can apply edgebanding to the sides of the substrate. Edgebanding is available in several species. If you can not find edgebanding in the species required, simply cut 1" wide strips from the veneer used for the main project and apply it to the edge of the substrate with Heat Lock or contact cement. Learn more about edgebanding by clicking here.
Sequence matching is the process in which the factory ships the customer sheets of veneer that reasonably match each other in terms of color and grain pattern. This option is great for large projects where consistency is critical to success.
The veneer is pre-sanded to 150 grit at the factory. However, many users find that they get a more even stain color if they sand the veneer one grit grade higher than the rest the project. So if you sanded the solid wood parts of a project with 150 grit sandpaper, you might consider sanding the veneered parts with 180 grit.
Paperbacked veneer can be cut to size with scissors or a razor knife. Two-ply veneer can be cut with a hand saw. Trimming a veneered panel is most commonly accomplished with a flush-trimming ball bearing piloted router bit. You can also trim the veneered panel on a table saw with an 80-tooth saw blade.
It is rolled up in a box and shipped via FedEx or USPS (depending on destination). The factory can usually get 5 to 7 paperbacked veneers in a 10" x 10" x 50" box. Two-ply veneers ship in a larger box because it can not be rolled as tightly as a paperbacked veneer. This box is usually 14" x 14" x 50" and is considered oversized by the carriers so the shipping rates are a bit higher.
If you order from VeneerSupplies.com...
Most paperbacked veneer species can take up to a 1" radius bend along the length of the grain and 5" radius bend across the grain. A light coat of veneer softener can increase the flexibility of the veneer and prevent splitting on tighter bends. In fact, I have achieved a 1/4" radius on the grain length when I treated the veneer with softener.
Most 2-ply veneers can accept a bend up to 5" along the length of the grain and 8" across the grain. Veneer softener is generally not effective on 2-ply veneers.
If you choose to apply a paperbacked veneer over bendable plywood, we recommend first applying 1/8" MDF to the plywood to add strength and rigidity.
Yes. When buying a backed veneer, be sure to specify a grade of AA or better. Anything less will have mineral streaks, bark, sapwood, or other defects. If the vendor can not tell you the grade, its best to assume the worst.
Since it is a real wood product, it stains just like a piece of solid lumber. However, many users find that they get a more even stain color if they sand the veneer one grit grade higher than the rest the project. So if you sanded the solid wood parts of a project with 150 grit sandpaper, you might consider sanding the veneered parts with 180 grit to get optimum color matching.
It is best to apply a protective finish to the veneer when the ambient humidity is 55% or less. Do not use heavy coats of finish. Instead build up multiple smaller coats which dry faster and trap less solvent under the finish. Additionally most catalyzed finishes will "check" or crack if applied too thick.
Water based stains and top coats are not considered ideal choices paperbacked veneer. If you must use this type of finish, be sure to apply a vinyl or acrylic sanding sealer to the veneered panel before staining and finishing.
This information applies to all backed veneers... 2-ply, paperbacked, and PSA.
Since there are many combinations of veneer, substrates, adhesives, finishes, and environmental conditions, we highly recommend testing a small piece of veneer with your application and finishing process before you begin the main veneer work.
Be certain to check for bubbles before applying your finish. If bubbles are present, this may be the only time to address these issues. The best way to check for bubbles is to place a powerful light (such as a halogen work lamp) beside the veneered panel and no more than 15 degrees above it. Look for peaks and shadows across the panel. Most bubbles can be easily repaired.
PSA and Contact cement: Place a piece of cotton or flannel cloth over the bubble and gently heat the bubble with a clothes iron. The heat will reactivate most contact cements. Keep the iron in motion to prevent overheating the veneer. Once the veneer is adequately heated, scrape the bubble again until the area cools down.
Heat Lock: Within 24 hours of application Heat Lock can be reactivated. Place a piece of cotton or flannel cloth over the bubble and gently heat the bubble with a clothes iron. Keep the iron in motion to prevent overheating the veneer. Once the veneer is adequately heated, scrape the bubble with a veneer scraper or block of softwood until the area cools down.
Cold Press Veneer Glue: When high quality cold press veneer glue is used with a vacuum press, bubbles are generally not a problem. In the event that a bubble does show, the ironing method described above will usually fix the issue.
I always use a paper backed veneer on the back side of my panels if the face side uses a paper backed veneer. Others say they never use a backer/balance veneer and haven't had any warping problems. I think this largely depends on several factors.