Coroplast??

[Kanvas Keepsakes]

Is this common to use behind the canvas as a backing?  I can hardly find any info on this on the net.  Is 4mm common for this?   How would you attach this ?  Screws?  Nails?  Glue?  Anyone know where I can buy this?

[bill t.]

Coroplast is similar to corrugated cardboard, but made out of plastic.  It is heavier and more flexible than the same size and thickness of corrugated cardboard.  Most of the cheap political signs-on-a-wire you see are made from 3 or 4mm Coroplast.

Because of the slight corrugations and general floppiness I would personally not use if for a canvas backing.  You would need to use adhesive to attach canvas to plastic, water based glues would not hold well.

I have several sheets of 7mm, 51 x 97 Coroplast that I use for the canvas coating process.  I tape canvas prints up to the coroplast, then coat them.  The 51" height allows 2, 24" wide pieces of canvas to be taped up together, a very nice feature compared to the 48" width of foamcore etc.  7mm is the minimum recommended thickness for this, 4mm is just too floppy to control when moving large sheets around the shop.

Edit...every plastic supplier has Coroplast.  My local Piedmont always has stock.

[Kanvas Keepsakes]

So Bill, what would be the best option to cover the back opening of my canvas wraps?  I think it looks better and I'm trying to gain a couple of big photographers locally that outsource all their canvas wraps.  Right now I use a white masking tape that I put to cover all the staples and make it look more clean.  I don't use stretcher bars I actually make my own using poplar wood and quarter round molding.  So the white tape looks real straight and formal around the back.  But I want it to look better with a backing.  Also want to include a hanging assembly like those little teeth looking hangers. 

[bill t.]

The backing question would get some interesting answers at thegrumble.com.  Stay off the "Warped Moulding Forum," just saying.

If you really want to seal the back Tyvek film is one possibility.  It does not suffer from the finger piercing issues one experiences with paper backing within the first 5 seconds of handing the piece to a customer.  Search "Tyvek" at unitedmfrs.com.

I'm not sure you need to do anything cosmetic to the staples or backs of the canvases.  It looks kind of arty just the way it is and of course you don't see it on the wall.  On stretched canvas it's a (arguably) good idea to leave the back of the canvas accessible so it can be tightened by water spritzing.

For about $1/foot you can get really nice stretcher bars from LinenLiners.com.  Those are the type you have to miter yourself, you won't have adjustable ends.  The canvas needs to be stretched right the first time, and be of a type that is not sag prone.  All of which is why I always mount canvas.

If you put ordinary sawtooth hangers at each of the two top corners at about 30 degrees you have an adjustable levelling system.  The hangers should be positioned to span the top and side bars.  Slide the canvas left and right across two mounting screws to adjust the exact level.  The link shows one that is probably too small both in length and size of holes.  You need sawtooth hangers that are at least 3" long and with holes large enough for #6 screws.  I'm sure The Grumble can give you a source.  You can also use so-called Wall Buddies for this purpose.  They cost more.  The downside of using sawtooth hangers is that they can damage other canvases if you stack them together improperly.  All such toothed hangers are taboo around here because we tend to be a little cavalier about storage at times, but honestly they are useful.  Don't use wire except for very small pieces, the canvas will lean out from the wall and look stupid.

[framah]

I use coroplast to back all of the canvas framing jobs that come in unless the artist specifically requests I leave the back open. I inform them that leaving it open to the world is inviting something to poke into the back of the canvas and damage it.

You can also use a piece of mat or a piece of foam core and they will do the same thing of protecting the canvas. As for using saw tooth hangers for ANYTHING.. it's not a good idea. Almost every piece that has come in and is in need of repairs from falling off the wall has been hung using a saw tooth hanger on a nail.

Using two of them doesn't lessen the chance of something causing the piece to fall off and crash to the floor.

A wire and at least one hanger in the wall is the way to go.

So to answer your OP, yes, you can use coroplast on the back. If you want access to "spritz" the canvas, you can screw it on rather than stapling.


...and DO head on over to the Picture Framers Grumble and be sure to check into  the "Warped" section. I'd say that we won't bite your head off, but truth is that everyones head has been bit off at one time or another but there is a wealth of knowledge over there.

[bill t.]

Hey!  People poke things through canvas from the FRONT!  It's so damned crowded in the space between the wall and the back of canvas, people don't like to hang out there much.

And, as I said, you gotta find BIG sawtooth hangers with holes big enough to take screws rather than nails.  Even a pair of #4 x 3/4 screws will support pretty heavy canvases, #6 is better.  But even worse than sawtooth hangers with nails is sawtooth hangers with the pathetic little bent metal prongs that are supposed to act like nails, those are serious bad news.

Whatever else, just make sure your customers don't try to hang your pieces from adhesive backed hanging hooks.  Those are now the ONLY wall hangers available at places like Staples and my local Walgreens drug store.  Estimated time-on-wall to failure...1/2 hour.

[Kanvas Keepsakes]

I use white tape to go around all the back side to cover up any uneven cuts or staples and make it look cleaner.  Any photog that buys canvas from me actually likes the way it looks instead of exposed.  As far as hanging since  I dont use stretcher bars pre-cut mine are made of solid pieces of poplar wood that dont have any kind if indention in the wood.  So just a solid nail right from the wall like my finger shows and no adjustment needed.  Once it's hung on the wall, who's gonna poke something through the back?  I guess if someone requests another way I'll switch but for now I'll continue using this route.  

[framah]

I just happened to pop in here again and read the last post. The reason for covering the back with something that won't allow something to poke into the canvas is, as I'm SURE you know, NOT referring to while it is on the wall!! Whenever anything is moved off the wall, the back is exposed to all sorts of things that might be placed against it or happen to fall against it or lean into it long enough to either put a dent in the canvas or even poke a hole thru.

Your idea of just using a nail in the wall and rest the piece on it, is actually one of the main reasons for stuff falling of the wall. A hook in the wall and a wire on the back create a combination that won't allow the piece to slip off. Having the nail head catch the wood just behind the canvas is asking for trouble.. again, poking or denting the canvas and possibly staining from rust over time.

The idea of the indentation in the wood you speak of is there for a specific reason. It goes to the front, ie: right behind the canvas so that edge of the wood isn't touching the canvas and causing a line or rub in the canvas. Many pieces of old art have come in with your type of setup and there is a visible line in the canvas right at that edge of the wood.

On the plus side, the tape on the back is pretty. Unnecessary and damaging to the canvas from the chemicals in the adhesive, but pretty.

So, tho you think you are doing things right, you really aren't. Please, go ask a professional framer about the right way to do it.   Odds are your customers don't know either and are expecting you to know and thus are assuming that you are doing it right.

[bill t.]

+1 about the tape.  In about 2 years the strip of tape on the bottom will mostly come off and be left dangling down from the bottom of the canvas.  It's never a pretty sight.

IF you are interested in your canvas remaining perfectly level on the wall for eternity, you might look into a scheme like you see with these WallBuddies.  You level the frame by shifting it left and right, so the two nails don't have to be exactly the same height.

If you can find simple sawtooth hangers about 4" long and with holes big enough for #4 or #6 screws, a pair of those positioned at an angle will work just as well for canvases weighing up to several pounds.

In truth it must be said that asking your average art buyer to put TWO nails into the wall at roughly the same height can be a stretch for them.  And that's on top of asking them to use a tape measure, and do fractional math.  So you need to provide detailed written instructions, and set things up so that all measurements come out to either even-numbered exact inches, or at least inches and a half.

Now, here's where it gets non-linear.  You should position one of the sawtooth hangers so the teeth can engage the nail.  But mount the other sawooth upside-down so the SMOOTH part rests on the nail.  Why?  Because every type of frame is going to stretch and contract and warp during its lifetime, which can pull the nails sideways and undermine their grab into the wall.  The upside-down sawtooth provides a low friction bearing surface, while the tooth-engaged sawtooth maintains registration.  That expansion and contraction is why I no longer use WallBuddies, but still approve the angled sawtooth concept.

Notice the picture for the W3300 WallBuddie shows them installed backwards.  Stupid photographers!

Or you can just put two d-rings on the vertical sides.  But that requires exactly positioned nails, label that "difficult for your average Joe Art Buyer."

[Kanvas Keepsakes]

Eeesh it's back to the drawing board for me!  As far as the indentation of the wood I meant the back part.  Not the part behind the canvas.  I use quarter round moulding on top of solid poplar to give me that rounded edge so the canvas does not rest on the wood.  I went to buy 2 sheets of mat board at a local art supply store . .$20!!  Wow . . I'm trying to keep my prices down.  I guess I'll play around with a few options see which is better.  If the tape does damage to the canvas on the back end where it rests on, what would that do to the sides and front over time?

[Colorwave]

I used to use paper backing on my stretched canvases until I discovered that it encouraged mold, due to poor air circulation.  Granted, I'm in the middle of the Pacific ocean, so we have a lot of humidity, but no more than any other coastal area. 

I find that cleanly stapled, nicely trimmed canvas looks quite presentable, and always use quality D-rings and picture wire on gallery wraps.  If you use a wire, and the two points are reasonably close to one another, they do not need to be perfectly level to one another, as the wire takes care of that.