Backdrop seam

[Daffey]

Hi,
I am making my own backdrop for a show and I was wondering which one is better, horizontal or vertical seam? The size will be 16' X 32'. I'm thinking of using canvas and the backdrop will be painted on. Any thoughts?

Thanks

[seanandkate]

All other things being equal, I would say a vertical seam just because backdrops are generally lit from top and bottom, so a horizontal seam might cast an ugly shadow. You might also want to consider the design on the backdrop itself to see if painted elements (horizontal horizen, or vertical brick wall, say) that might lend themselves to camoflauging a seam.

[Van]

Horizontal. Always Horizontal. Almost any seamed drop you would buy will have a horizontal seam if it's not one piece.
You should be able to find 198" wide canvas, or scenic muslin though.

[kicknargel]

Typically backdrops have a horizontal seam, because when hung the weight of the drop and bottom pipe will pull that seam tight. On a well-built backdrop the seam is all but invisible.

Backdrops are typically made of heavy-weight muslin. Canvass is unnecessary. You can get 120" wide muslin readily at a theatric supply or RoseBrand.com: Theatrical fabrics, stage curtains, backdrops, hardware and accessories. Maybe also at a fabric store. For much more money you can get wider widths and not have a seam at all. This is good for cycs but not usually necessary for painted drops.

Here are the steps I use in building a backdrop:

-lay the two pieces of muslin together face-to-face and stitch the horizontal seam. Use a heavy-weight polyester thread.
-lay out the drop on the floor and snap lines for the sides and bottom (or top)
-fold over the sides and top to the snap line and iron the edge (makes hemming easier). cut/tear of excess if it's more than a couple inches
-double-fold the hems (so the cut edge gets tucked inside the hem) and stitch the hems
-stitch jute webbing (get it where you got your muslin) along the back of the top. One stitch line at the top and one at the bottom of the jute. Grommet through the jute. (not through the stitch line)
-Take a piece of excess fabric about 12" tall and the length of your drop. Stitch it into a tube. Turn inside out so the seam ends up inside (run a string inside the tube as you stitch it to help turn it inside-out). Stitch this to the back of the drop at the bottom, such that the bottom of the pocket will be an inch or so above the bottom of the drop. This is your pipe pocket. You want it to be hidden behind the drop but just at the bottom.
-Lay the drop back out on the floor flat and square. Staple along the edges every couple inches. The drop will shrink a lot, so staple it well.
-heat a pot of water and mix in laundry starch (or corn starch). Brush this into the drop (many people use a broom to work it in). This will size (shrink) the drop. You can also use watered-down paint, but starch works better.
-paint away!
-to be flame-retardant, you should use an additive to the paint (Rosco, from your theatrical supplier), then spray the back of the drop with a proper retardant after painting (a different Rosco product, or others). You can also use FR muslin, but it has a tendency to leech out the salts as you paint.

Let me know if anything's unclear! Good luck!

[Van]

Excellent post Nicholas !

[Grog12]

All other things being equal, I would say a vertical seam just because backdrops are generally lit from top and bottom, so a horizontal seam might cast an ugly shadow. You might also want to sonsider the design on the backdrop itself to see if painted elements (horizontal horizen, or vertical brick wall, say) that might lend themselves to camoflauging a seam.

Here's the other flaw in this logic apart from what Nick and Van pointed out. Any lighting designer worth his salt won't light a seamed drop from the back which is when you'll get that shadow.

[Van]

unseamless .

" Un-Seamless" as in "no seam" ? Or did you improperly apply a Double Negative ? Hmmmm ?

[Grog12]

I knew it was wrong when I typed it Van....A drop with a seam...

[derekleffew]

" Un-Seamless" ...

...A drop with a seam...

I like "seamed drop" better than any of the above.

[Daffey]

Thanks guys for the replies.

[Van]

I like "seamed drop" better than any of the above.

and here I thought I was channeling you for a moment Derek.

[JLNorthGA]

Would like to purchase one (or more) drops on which to paint scenery. I've gotten quotes from BMI Supply, I Weiss, Rose Brand and Georgia Stage Company.
Size would be 18' H x 40' W, grommets w/ ties at the top, pipe pocket at the bottom. I Weiss is quoting seamless, the others are quoting seamed.

First - this drop is to be painted. I've no real objection to seams, as I figure they'll be covered with paint anyway. But if there is a real advantage to getting seamless, then I'll order the seamless.

Second - everyone is quoting heavy weight muslin - I Weiss also quoted canvas as an alternative (seamed). Muslin works for me (especially as it is cheaper) - unless there is a real reason to go for canvas.

Prices quoted were $450-$650 for a single drop - shipping would be extra.

Should I get more quotes or do y'all think these are reasonable enough?

[Footer]

Go seamed, unless you are backpainting for reveals there is no reason to waste the money on seamless. Heavy weight muslin will also be fine. 450 sounds about right for that type of thing.

[kicknargel]

Concur. You might also want to try Garriet's for a quote.