What is "Cotton Duck" canvas ?

#whattheduck….. #gettingyourducksinarow

CANVAS

/ˈkanvəs /

Der. 13th century Anglo-French “canevaz” & old French “canevas”, der. Vulgar Latin “cannapaceus”

Or “made of hemp”, der. Greek : κάνναβις

DUCK

/dʌk/

noun

1. 1.

a waterbird with a broad blunt bill, short legs, webbed feet, and a waddling gait……..

D-U-C-K….. (not D-U-C-T !) simply comes from the Dutch word “doek”, meaning “cloth”.

Canvas comes in two forms: plain and "duck".

Duck is a heavy-duty cotton fabric, sturdier than plain cotton and holds shape better than standard canvas.

Both duck and plain canvas are standard (plain)-woven fabrics, but there are a few differences between them:

Duck is more tightly woven than plain canvas.

• Duck is graded on a scale of 1 to 12, with 12 being the lightest fabric and 1 being the heaviest. (Classification system, established in the 1920s.)

• Duck is made exclusively from cotton, hence sometimes referred to as cotton duck canvas or cotton duck fabric.

By definition, there are two types of "canvas"

Linen is produced from flax plant fibers (and substantially more expensive since it is harvested by hand in Europe.

Cotton canvas is produced from the white “candy floss” bit, found around the seeds of cotton plants (and more affordable, since it is commercially harvested)

Cotton 'Duck' only really became popular round about the 1850’s, with the advent of acrylic paint, however one of the earliest surviving oil paintings on duck canvas was one discovered in 1410, Madonna with Angels, in Berlin.

Under the Cotton category, you get 'plain' and 'duck' cotton …..which is how we arrive at the term “Cotton Duck”, the cloth we use to manufacture our signature brand canvas.

The reason that we use the “Duck” and not the “Plain” variation is that Duck threads are a lot more tightly woven, which is very important. Looser threads pose the risk of over-stretching or even tearing when stretching onto a frame. In addition, the tighter your weave, the better and more consistent the application of your primer.

Duck is flexible – and it’s strong.

In weaving a canvas, the plain vs. the twisp weave is used since it is the strongest and most hardwearing of the weaves.

Cotton duck, uses a variation of this plain weave, called the “basket weave” – where two or more threads are bundled and woven (vs. the “one-up-and-one-over” or “balanced plain weave” variation), again for added strength and durability, and ultimately to facilitate the sizing, priming and sanding processes we apply to arrive at our finished product.

We use a 340gsm grammage in our signature brand.

This is where I have to mention how especially vital it is that the cloth is stretched properly, especially for larger paintings. At ETH Canvas, our years of expertise in this field have enabled us to supply you not only with professional advice in this regard, but bespoke customization where required.

Close attention is paid to the construction of our stretchers and the technique employed to stretch the cloth. Every tiny detail counts - right down to the tools that we use - our stretching pliers being especially imported from Germany since we have found that locally supplied pliers not only tend to damage the canvas , they are just simply not strong enough for the techniques we employ.

Without getting too technical, a canvas needs to be “sized” (especially cotton) before priming.

This is the process by which a layer of gelatinous material is applied to the raw canvas prior to priming, so as to seal the pores in the surface of the cloth. This ”waterproofing” is vital in preventing fluid (paint) from seeping through into the fibers of the canvas and ultimately rotting the cloth. It also obviously reduces the volume of paint you need.

The primer we use does both. Our canvasses are expertly primed (and sized) resulting in a texture that is perfect for any medium. In addition, and to bring you back to point, our particular choice (weight and weave) of cotton duck contributes to the efficacy of this process: Tighter threads, woven in a stronger pattern. It’s quite simply a winning combination!

By no means disregard the natural beauty and smooth, stiff painting surface provided by linen, the qualities that originally seduced our masters of old … but when it comes to canvas - the quality that is an ETH Canvas remains unparalleled.

Give your work the gift of immortality with an ETH Canvas as it transports you through the realms of your creative process. Perfectly smooth, non-absorbent and expertly stretched, with just enough tooth to ensure maximum reflection of colour and light.

We guarantee it. We are artists ourselves. We know exactly what you need in a canvas.

What is a canvas with "wedges" and how does it work?

"Why would you choose a canvas with wedges ? Surely if it is stretched properly, they're unnecessary?"

This is true, to a degree. Ultimately, whether to choose wedges or not depends on a number of factors, including the dimensions of your canvas; its profile (depth),; your medium and painting style; whether the finished work is due to be transported at any stage; handling, geographical location with respect to environmental & temperature changes (sunlight, cold and humidity can all affect the fibers of your canvas) and, as it becomes heavier during the painting process, the cloth may move and loosen, regardless of how perfectly it was originally stretched.

But that's not all that properly made, installed and functioning wedges are good for ... another fantastic benefit is that a wedged stretched can be dis- and re-assembled. This is especially handy for art that is exported in a tube - and largely facilitates the re-stretching process once your work reaches its destination (especially given that decent stretching facilities are often either lacking, sub-par or extremely expensive abroad)

Wedges, "spacers", "chocs" or "keys" are adjustable “wedges” of wood that are fitted into the corners of canvas stretchers. These are used for “re-tightening” your canvas should it have become loose or ‘bouncy’ over time, during transit, as a result of environmental fluctuations or simply because of pressure applied to it during the painting process.

Most pre-made, cheaper canvases have “slots” cut into them (where wooden or even plastic wedges are supposed to go) and the wedges themselves supplied separately, often loose within the canvas packaging... leaving you with the often impossible job of fitting them into their ‘designated spaces’ before being able to tap them in.

We do things differently at ETH. We used a unique dovetail system which provides for the wedges to be pre-fitted at all the necessary points (8 wedges installed in each corner, and 2 wedges installed per cross bar). No glue is used in the wedge-system, and only a single "stabilizer" staple which is designed to pop out when the wedges is tapped in. This alleviates some of the stress of ensuring that the tightened canvas has equal tension all round and that they don’t splinter or crack the corners of the frame when you are tapping them in (a common complaint I hear time and again). In addition, we use only kiln-dried obeche timber (so most of the moisture has been removed) which is knot- free eliminating the natural tendency of cheaper "knotted" timber stretchers to split - usually at the moment you try and whack in a wedge.

Each set of our wedges are individually cut during the manufacture of each stretcher and I can promise you - they work like a wedge is supposed to! ETH Canvas is one of few (if not only) local supplier that are able to manufacture box (deeper edge) frames with a wedge system – right up to a profile of 50mm. In addition, and unlike other systems, there is little to no chance of damaging the canvas when you hammer the chocs in, since they are designed as a complimentary functioning set and sanded to ensure they don't damage your cloth. Another anomaly of pre-made, mass-produced chocs supplied with cheaper canvases.

A nicely tightened canvas vibrates like a drum membrane if you flick the center of it with your fingers. The less vibration, the more tightening that is required.

How to use a wedge-system to re-tighten a stretched canvas

If your canvas is unprimed, do NOT use the wedges until priming is complete - the priming process itself causes contraction of the cloth, rendering the canvas tauter on the stretcher.

For smaller canvases and using a rubber hammer, gently tap the end of both wedges into each corner, working your way around to each corner. As you tap the wedge, the space at the corner of the stretcher may increase. Don't be alarmed. This means its working.

It is advisable to check the progress of your tightening after each wedge position and that you stop once the canvas is taut enough – once the wedge is embedded, it cannot be removed and if you "over-tighten", it can create too much pressure within the stretcher structure and end up warping your frame.

NB - For larger canvasses, you need to expand the facing stretcher bars first, to keep the tension on the canvas even. So, tap the wedges that push one of the stretcher bars in one direction, then rotate the canvas and do the same for the wedges pushing the opposite bar, in the opposite direction. Then, repeat for the other sides.

It is never a good idea to tap too hard, for obvious reasons, since you always run the risk of overcorrection or the wood splitting – tap means “tap” (not bludgeon...). Please be wary of this, and rather tighten and rotate a second time, to be on the safe side.

How to extend the longevity of your painting.

Keywords are: COOL and DRY

AVOID

- Direct sunlight or sudden or extreme changes in temperature

- Leaning panels and stretchers against walls and directly on the floor (use blocks to raise them)

How to roll a painting for transport

At no point do I claim to be an expert on anything, but in my humble journey, the need has arisen to know how to do this (among other things...) properly! .. hence, through trial and error and a bit of research, I thought I would share in case it comes in handy for anyone. Ultimately, it is up to you to do the homework and ensure that you are using the correct wrapping technique for your particular work, depending on the medium, size etc. (most of you probably know all of this already - and any additional input is always welcome! Information is king, after all!) This method obviously works for acrylics and recently painted oils...aged paintings should not be rolled if you can avoid doing so, since their paint film is no longer flexible. It is not advisable to roll paintings exceeding 1.8 m on their long side. MOST importantly - make sure your painting is DRY. It is not worth letting your or your client's impatience make you send it too early - you don't want the paint to crack and peel later! As you all may know, with oil painting, each additional layer of paint should contain more oil than the layer below to allow proper drying. This is not a hard and fast rule of course, and it is ultimately the quality and type of oil that leads to a strong and secure paint film, as well as the drying medium, if any, that is used, and even the paint colors themselves. On average, and especially on larger works, oils can take between 6-12 months to cure properly. Once dry, designate a flat, clean surface to work on (table or section of floor). Cover the area with a clean protective sheet. Place two - three sheets of wax paper (a spare piece of canvas - not too coarse in texture - works best) down, ensuring that the area is at least 5 cm bigger than the outside edges of the painting itself. If you have to overlap the sheets to get the area big enough, ensure that the overlapping edges do so with at least 4 cm. Place the painting, FACE DOWN onto the wax (or glassine) paper. Paint, once dried onto linen, has more flexibility when curving slightly outwards than when being turned in on itself and being "squished" together. If rolled outwards, the painting is stretched, and if there is any hairline cracking, these will be invisible when the painting is laid flat again. Rolling oil paintings inwards causes the paint to crease, chip or flake, which become clearly visible when the painting is laid flat again. You want to roll along the short edge, since this gives the packaged structure more stability than a longer one. Carefully roll the painting as loosely as possible - ensuring that there are no lines or bends in the buffer paper. If this happens, unroll it and start over. Do not fold the painting when you start rolling, as this can damage the painting - try and make the rolling action as smooth and consistent as possible. First prize is to buy two tubes - one to roll the painting around (called a "roller")and one to put the rolled painting into. It should be as wide as possible and be longer than the ends of the painting. Be sure to protect the painting from the roller with either a polyethylene foam such as Plastazote, or Dacron wadding covered with clean white cotton fabric - especially if the painting is textured and has irregularities in the painting’s thickness. (PVC pipe or carpet roll tubes also work well - as long as they are as solid as they are lightweight) DON'T use any material that may be difficult to remove - for example clingfilm or tissue paper. Also, don't use any material that is coarse or textured (like bubble wrap) against your painting, since this can imprint itself onto your painting. The art must also be able to breathe...If using loose pieces of canvas, ensure that is it a fine weave. No printed material like newspapers or wrapping paper - only acid-free paper is an option. Once rolled, use (a good quality!) tape at regular intervals to secure your roll. Don't attempt to use strings to secure the roll, since these can place undue pressure on the painting and cut into the painted layers. A great tip is to fold the end of the tape into a "tab" so that the unpacker doesn't struggle to remove it. If the tape is difficult to lift, the unpacker may end up tearing the paper, and damage the painting, in an attempt to unwrap it. Another good idea is to use red or blue colored tape - which is easier to see (and locate) than transparent tape. When it comes to your tube, a heavy duty mailing tube is always best. Look for one that is at least 10 cm longer than the shortest side of your painting when flat. The width of the tube of course depends on the diameter of your work when rolled : regardless, the tube will need to be at least 10 cm - 15 cm wide (if not wider, depending on the size of the painting - recommended minimum diameter is actually 20 cm, regardless of the size of painting). If the painting is very long, it will be thicker when rolled, so aim for your tube to be at least 10 cm - 12 cm wider than the diameter of your rolled works. Also, make sure you have proper end caps for the tube - simply taping it shut will damage the painting. You need to prevent the painting from moving around inside the tube as well as to prevent moisture from getting in. This is where bubble wrap does come in handy. With the bubbles facing outwards (they provide excellent "traction" between the painting and the tube, further reducing possible movement inside), roll your rolled painting in the bubble wrap until enough cushioning is achieved so as to allow the painting to fit snugly in the tube. Tape again. Leave a 10cm piece on each end which can be folded over and taped, like a present, to further protect the ends of your painting - be careful not to squash the ends in this process. Remember, if you struggle to get your painting into the tube, the unpacker is going to struggle to get it out....RATHER BUY A NEW TUBE. Secure the lid of the tube and secure with tape for additional security. Viola! Bye-Bye Baby! :-) (It is advisable to clearly mark the tube FRAGILE, and clear instructions that its handlers carry and store it in a VERTICAL position - within reason obviously, but as far as possible, since lying on its side in a horizontal position can also place undue pressure on one side. The idea is equal distribution of pressure throughout, and as far as possible) Although it seems like a viable storage option, be sure to tell your client to unroll the painting immediately after transport. It should be stored flat if necessary, and be re-stretched on a new frame as soon as possible after receipt. I hope this can be of use to you soon in future when you send that next commission of yours to its new home.....!