Painting with wood: knife cutting marquetry basics
The use of marquetry to adorn furniture began in Asia Minor, but was given a new life in Europe during the 15th century. It was a thing of royalty and the church, as they were the only ones who could afford it. It impressed guests and family of political and religious leaders then, and there’s no reason why you can’t use some of these techniques to impress your friends and family today. Though it can be tricky at first, with a little practice it’s not beyond most woodworker’s skill level. Take it slow and start simple; you’ll be surprised how much marquetry can add to your next project.
Marquetry is the cutting and assembling of different pieces of veneer into a sheet that can be pressed onto a core. There are generally two ways to produce marquetry – with a knife or with a fret saw. I will focus only on the knife here. Although there are different ways of producing marquetry with a knife, I’m going to stick to the specific technique I use for most of my marquetry work. I find it’s fairly simple, doesn’t require any fancy tools and can give surprising results, quickly. A knife works best for regular or thin veneers as well as straight-grained woods. It’s also great for cutting straight lines. One of the most important reasons to use a knife is because it’s easier to control than a fret saw. And besides, you probably already have a knife around the shop you can experiment with. Just make sure it’s sharp.
I always start be making a full-size drawing of the design I want. The drawing can be on any material, as I just want to have a design to work towards. It also helps me understand proportion and placement of the pieces I’m going to cut. This is especially important in the early stages, when there’s nothing but a blank sheet of veneer to guide you.
Knives are Important
Whatever knife you choose, keep it sharp. I take a standard #11 X-Acto knife blade (right) and modify it to have a more blunt end.
Draw Right on the Veneer
To make things easy, mark light lines on the veneer then cut them out. When making multiple parts, I number them to make sure they go back in order.
Cross Grain Cuts are Tricky
Sometimes you will need to score the grain first then make an additional one or two passes to sever all the fibres.
This is the perfect way to add depth and shadows to your work. Practice with scraps first to get the right temperature and technique down.
Veneer tape will hold all the pieces together as you work your way along. A bit of moisture on the underside of the tape is all that’s needed.
A Helping Hand
With low-tack tape to hold the bamboo in place, I cut the mating mahogany edge. There are times when having a couple of relatively heavy (block plane) or long and straight (ruler) objects around is a good idea. They can act as another set of hands, keeping the sheet flat.
The Foreground is Usually Last
To keep perspective as realistic as possible you will need to let in the “closest” pieces last so they will overlap the rest of the image. I also leave small items that only mate with the background, like this bamboo leaf, until the end. I prefer cutting the piece then cutting the cavity, but it can also be done the other way around.
The Most Important Tool – The Knife
You can use whatever knife you find comfortable, as long as it’s sharp and you can control it easily. Most people, including myself, use an X-Acto knife handle with a #11 blade. I even spent the extra few dollars and picked up the upscale model that fit my hand nicely. I modify my blade slightly to give me a bit less flex at the tip. It’s also easier to sharpen – something I do regularly while working. A sharp knife is important. People’s knife preference is largely personal, so experiment with a number of different knives and methods of sharpening. And don’t be afraid to spend a few dollars on a new knife. It might make a big difference.
Cut with the knife blade perpendicular to the veneer and cutting surface. In theory, the beveled blade produces pieces with a slightly angled edge, but at the end of the day I find it’s not a big deal. Maybe when you’re an expert in the field of marquetry you can concern yourself with these tiny details. If the largest gap in my marquetry work was 1/128″, I would have been more than happy when I was just learning. Heck, even now I would take those results! A grip very similar to holding a pen or pencil should be employed, as it’s comfortable over the long term, and you have a lot of control over the knife. When cutting always orient the grain of the veneer so you’re cutting ‘downhill’. There will be much less tendency for splits to occur in the piece you’re keeping. Cut on top of a piece of Masonite or Melamine-covered particle board. When it gets too damaged, just cut a new piece.
Layout and Cutting
With the full-size drawing in front of me, I start to draw some of the larger, background pieces out on the veneer. It may be handy to use tracing paper to transfer the design to the veneer. Don’t leave a heavy, dark pencil line when you draw on the veneer because it may return just as you apply the first coat of finish. I think a fine mechanical pencil is a must for almost every woodworking application, but especially here. It’s accurate and always sharp. While drawing these cutting lines on the veneer, keep grain direction in mind for two reasons. The most important reason is that the grain direction will go a long way to tricking everyone who sees the finished piece into thinking it looks even more alive and life-like. A secondary reason to consider grain direction is because you have to eventually cut these pieces out. Pieces with short grain will be more difficult to keep intact, but it might be worth it for the overall look of the piece. If you can orient the pattern in such a way as to keep the short grain to a minimum, especially for your first project, you will thank yourself. If the piece has some short grain, you can apply veneer tape or Scotch tape to the area before you make a cut. It will help hold those fibres together until the piece is pressed to the core.
When cutting across the grain, you may have to make two or three passes in order to cleanly sever the grain. Don’t force it with one pass or you’ll likely ruin the piece you’re cutting.
Shading individual pieces adds an incredible sense of depth to your work, and with a bit of practice is fairly easy to do. Put some clean, dry sand in a pot. Place the pot on a hot plate (or a stove element) and allow the sand to heat up. Determining the correct temperature requires some experimentation. With scraps of the same species of veneer as in your project, test each piece by dipping it into the sand. The deeper you go, the hotter the sand is, and therefore the darker the shading will appear. If the sand is too hot, the piece will tend to shrivel and crack. The correct temperature will allow you to dunk the piece in the sand for a few seconds while manipulating its position. This movement gives a shade line that fades away, giving a better 3-D effect. It will take a while for you to dial in the right temperature, and get comfortable with this technique, but it’s nothing but practice at this stage. As you’re sand-shading, do your best to have consistency. If one tree trunk is shaded on its left side and the tree beside it is shaded on its right side, the image will be much less believable. It’s a simple, but important thing to keep in mind.
When a piece of veneer is put in hot sand, most of the moisture is removed from it, causing it to shrink. Sometimes I will shade a piece first, then cut the mating sections, to ensure the fit is tight. You can also cut the piece slightly oversize, shade it, then cut it to final size.
I use tweezers to hold the piece of veneer, as even touching the sand for a split second is painful. Hold the piece away from the area to be shaded, as the metal tweezers will suck away heat from the piece of veneer, causing blotching where it was being held.
Sand shading should be done over the duration of the project on a “need-to” basis, so it’s good to have a hot plate on at all times. Otherwise, you forget what piece goes where and these little pieces start playing tricks on your mind. One final word of caution – don’t go overboard. You don’t want too much of a good thing.
Start to Assemble the Pieces
Once you have a number of pieces ready to go, you can start to assemble them with veneer tape. Some people use a tiny dab of glue on the mating edge of the two pieces to help keep the edges aligned after taping them together, but I have never had the need to try it. I find proper veneer tape is strong enough to hold the pieces securely, allowing me to pass on the glue at this stage. Feel free to use low-tack painter’s tape to temporarily hold pieces in place so you can cut or assemble different sections. This tape acts as a third hand. It should be removed before pressing, so don’t apply veneer tape over it.
I tear off a bunch of small pieces of tape so they are ready and waiting. With a damp sponge or paper towel by my side to moisten the tape and activate its glue I start assembling the pieces, keeping them as tightly together as possible. Before pressing the sheet to the core I like to make sure all the seams are covered with one layer of veneer tape. This stops glue from squeezing out, and helps keep the work together during pressing.
Depending on the design you may have to assemble a number of pieces then cut out the cavity where those pieces will go. That was the case with the bamboo marquetry I turned into a headboard. I cut, shaded and assembled all the maple bamboo sections, then let them into the mahogany background. It was far easier to work with the pieces of bamboo taped together, as opposed to each piece individually. Each situation will call for a slightly different approach. At this stage, just continue cutting, shading and assembling the pieces similar to a jig-saw puzzle. Sometimes when the sheet you’re working on gets a bit large it may tend to curl. I use heavier objects to keep the veneer surface flat, so the sheet will press flat when complete. I also use long, straight strips of plywood or a straightedge to help hold an area down while I’m cutting or assembling pieces.
I usually leave smaller, foreground pieces that I can let into the surface until last. This allows me great precision when placing them, as sometimes the best location for them can be slightly different than in the initial drawing. You can even use what’s called the ‘window method’ to cut these, and many other pieces. To do this, you first cut out the cavity. Then place the piece of veneer you want to let into the cavity underneath it. Shift the upper piece to see what grain orientation will look the best, then mark or cut out the piece through the opening.
It’s easy to say, but try not to get frustrated. If you find you can’t for the life of you keep the gaps to a minimum, don’t be too hard on yourself. Once the piece is pressed to the core the glue has a way of working into the seams, helping to fill gaps and level the surface. It will not fill ⅛” gaps, but it will improve everything just that little bit. And even more importantly, with a bit of practice you’ll see an improvement.
Finishing up The Piece
Some people feel marquetry should only be used to ornament furniture. Although that’s what I usually do, there’s nothing wrong with ‘painting in wood’ with the end goal a piece of wall art. Whichever way you choose to use your marquetry you will have to mount it to a core. I like MDF for its flat and stable properties. If you’re going to use this panel in a piece of furniture keep in mind it doesn’t accept and hold hardware very well. Baltic birch is a bit less stable, as it likes to twist, but it does have a fairly even surface and holds hardware much better. Particle core is an okay choice.
There’s not enough room here to go into all the pressing methods, but I will give you some guidelines. Although it’s somewhat expensive, I use a vacuum bag for virtually all my pressing needs. It’s fast and easy, and opened a number of doors to me when I purchased it. The basics of pressing – no matter what method you use – are to apply even pressure across the face veneer, core and back veneer and to finish the edges, if they will be seen. A back veneer must always be used to keep the panel balanced and flat. There are many ways to do all these things, but for starters, keep it simple. Clamps and slightly curved cauls are the way to go. A dry run is mandatory, as you will be potentially juggling dozens of clamps, numerous cauls and freshly glued veneer that wants to curl. At least a couple platens sized slightly larger than the core are crucial to distribute pressure. The surface of these platens needs to be even, so no imperfections are transferred to the finished piece. To stop the finished piece from adhering to the platen use a thick sheet of paper between the face and back veneers and the platens. I use a large roll of craft paper, which I cut to size, but newsprint can be used. The only downside of newsprint is ink may be transferred to your piece of marquetry, causing staining. This is especially true if you use too much glue.
I almost always use PVA glue to press panels and have had no problems whatsoever. Apply an even coat that you can barely see the core through. Keep the veneer glue-free until it comes in contact with the core, otherwise the veneer will curl dramatically. To much glue and the veneer will buckle, even underneath all that pressure. You will also get a lot of squeeze-out onto the finished surface.
Once the piece is dry scrape the veneer tape off the surface.
When the vast majority of tape has been removed you can use a sander to level and finish the veneer. Sad to say, but many great works have been ruined at this stage. If you sand too far you will expose the core, and ruin all your hard work. Sand with care, especially close to the edges.
Tips for Successful Cutting
Cross Grain Cuts are Tricky – Sometimes you will need to score the grain first then make an additional one or two passes to sever all the fibres.
Rob is a studio furniture maker and the editor at Canadian Woodworking & Home Improvement.