Hey guys,

Let's say I have a backpack that is 12" wide by 20" tall. I want to sew a mesh pocket to the front of the backpack (the side facing the hiker behind me) with an elastic band at the top to keep the contents in place.

I am trying to figure out the size of the piece of mesh I should cut to have a roomy but not saggy pocket.

For example, If I cut the mesh the exact size of the backpack (12" wide by 20" tall) there would be no room in the mesh pocket to store things.

The front pocket would store items such as a wet tarp. The pockets on each side would store items such as a water and fuel bottle.

Recommendations on the type of mesh to use (nylon, polyester, etc. and hole size) would also be appreciated.

Thanks for your help,

Nick

Nick, Check out the Gossamer Gear G4 instructions Here.

The G4 front panel material is 12" wide and the pocket material is 15" wide (including seam allowances).
I have a modified G4 with 14" wide pocket material on a 12" front panel. It will easily 'billow out' enough to hold a rain jacket, poncho or small tarp. Height is up to you.

I think if you are not using the pack to capacity and want to cinch it up across the front for stability, too large/tall of a front pocket can be a hindrance.

I've used nylon macro mesh from The Rainshed in the past. It doesn't have much body (too soft). Poly mesh is stiffer and probably more abrasion resistant. The lycra mesh on my GG Vapor Trail has held up well. I used lycra mesh on a recent project and it was easy to work with.



Hope that helps.

Edited by Lancem on 05/17/2009 18:34:59 MDT.

another thing is when you cut the mesh use to same width top to bottom. if you taper it your pocket wont have much volume from the middle down. look at how MLD does it. notice the folds or pleats on the bottom of the mesh pocket seam.


BTW your gonna have to show us pictures when your done.

Edited by Steingass on 05/17/2009 09:41:53 MDT.

Thanks a lot for the helpful information :-)

Matthew, just to make sure I understand you correctly, do you mean that if the mesh is, say, 14" wide than it should also be 14" tall?

Slick backpack you got there! Thanks for the picture.

Nick

the width of the pocket material should be the same on the top and bottom. it doesnt matter how long it is. can you see the pleats near the bottom of the mesh packet where he folded the excess material. thats so the pocket can expand at the bottom too. but back to your original measurements of 12 x 20 if you wanted to know a rough estimate of cubic inches just multiply length and width then the depth of the pocket so a pocket with 1 inch of depth would go like this. 12 x 20 x 1 = 240ci. whatever depth you enter you need to double it then add it to your original width then add an inch for seam allowance like Lance Marshall said so 1" depth x 2 = 2 + 12 = 14 + 1 = 15 total width of pocket fabric needed. but this is rectangular volume. you pockets volume will be more crescent shaped. more depth near the center and less and less as you get closer to the sewn edges curved around the circumfrence of your pack.

Edited by Steingass on 05/18/2009 06:15:43 MDT.

I think I know just where you are going, how much is enough. You do not want the pocket to be flopping in the wind so to say.
My last pack I made had a front pocket of 12X15. I made the mesh 15X15, pleated the bottom to take up the slack. What I discovered was that when the main compartment is filled it bows out (like your picture) and takes up most of the front pocket space. Just means that when you fill your front pocket it lowers main pocket volume.
If I had it over to do again I would go an extra inch in width (12" wide pocket would be 16" of mesh + seam allowance), keep the elastic top and have elastic lacing across the outside of the pocket to secure whatever you put in there.
my 2 cents
-Dale

I really appreciate the suggestions so far. I am thinking of going with a 15-16" wide piece of mesh (including seam allowance) for a 12" wide pocket.

What size elastic do you suggest using at the top of the mesh pocket (3/16", 3/8", etc.)? I have seen some backpacks fitted with round shock cord and other backpacks fitted with flat elastic. I would think the flat elastic would be much easier to sew into the seams which would prevent it from ripping out.

Thanks,

Nick

Edited by nkline on 05/23/2009 12:16:43 MDT.

*bump-a-roo*

Nick,

I've used shock cord, 1" fold-over elastic, and 3/4" non-roll elastic. The shock cord was hard to sew through and finish. I intended to use the 1" fold-over as the finished edge of a pocket but it was difficult to stretch it and sew simultaneously. I ended up just running it through a sleeve. It tends to fold and 'roll' inside the sleeve but does hold the pocket opening snug. The 3/4" non-roll is the best I've used so far: easy to sew through, requires a relatively small sleeve, resists rolling, and holds well.
On the other hand, the elastic in the MLD pack pictured above appears to be much smaller than 3/4", so perhaps that's all you need.

-Lance

Edited by Lancem on 05/29/2009 20:50:11 MDT.

pleating the mesh isn't necesary if you use a stretch lycra mesh right? the stuff I just got in the mail today for my Ion has nearly 1 inch of stretch per inch of fabric in one direction and about 3/4 inch of stretch per 1 inch of fabric in the other direction. Granted it weighs more per oz than than nylon mesh, but 1/2 the weight of polymesh per yd. I figure 2 8x6 panels and one 9x15 for the back of the ion will only add roughly .66oz plus the elastic strip on the top of the pocket maybe .05oz... a whopping .71oz to a 8.75oz 2008 model Ion...

"pleating the mesh isn't necesary if you use a stretch lycra mesh right? the stuff I just got in the mail . . . "

Not to get too off topic, but where did you get the stretch mesh, and how durable does it seem?

Thanks in advance.

http://questoutfitters.com/mesh_fabrics.htm#LYCRA%20MICRO%20MESH

It doesn't look bomproof or anything, but I just dragged the closed scissor tips against it with pressure and it kind of slid and didn't leave any snags. Also tried shoving the scissor tips in while pulling the cloth away, It caught but then slide along the fabric. It's a very silky and slick feel to the touch of the fabric, think lingerie but a lot thicker. I'm sure it will do fine for durability in a lightweight pack. Hell, if you snag it you have a couple inches of slack before you are actually putting pressure on the mesh. The stuff is 3.7oz/sqyd which is less than the dyneema at 4oz/sqyd... So in moderation it wouldn't be super heavy, I should get the chance to start sewing next week I'll post pics in a separate myog post.

Edited by rooinater on 06/04/2009 13:59:03 MDT.

what the mesh looks like to the light.


Stretching, upon actually measuring both sides can stretch the same but one really only easily stretches to 1.75" from an inch of fabric while the other way more easily stretches to 2" from 1" of fabric.

About to start sewing on a modified G4/Burn/Circuit style backpack and I've got the same lycra mesh from Quest Outfitters.

It strikes me as much heavier (3.7 vs 1.9 ozs?) than the silnylon, even oxford, that I'm using elsewhere.

Glad I found this thread because I spent the night debating the width of my mesh.

I came to the conclusion that even the somewhat stretchy lycra mesh will need some extra width to really hold items. I think equal width and pleating is the way to go too. I'm going to use the shockcord in fold method because that's what I have.

What do folks think about a pocket that's mesh on the bottom and silnylon on the top to save weight? Is that weight obsessive? Is silnylon more durable than this heavy lyrca mesh? Will half and half be ugly?

Edited by ctwnwood on 07/10/2011 01:19:39 MDT.

Lyrca has a lot of stretch to it. Using a pleat or not really depends on what you intend to put in to the pocket. On my last two packs,I have used not pleats on the side pockets, as I like a really tight side, and I used a pleat on the front for bulkier items.

The mesh/nylon combo is just personal preference. If you think it will look good, or more importantly be functional then go for it.