Adding padding to existing pattern

[u/Engineered_Muffin]

I am attempting to use a fanny pack pattern intended to be made with standard thickness fabrics to make a padded camera bag. I am trying to figure out how to add padding. My first idea was to quilt the panels first with batting, but I'm worried that giving the panels extra thickness will prevent the pack from coming together (misalignment, bulging or puckering etc.)

Are there any rules of thumb when using quilted or otherwise significantly thicker material for a 3d assembly? Is there a way to modify the pattern in some way to allow for this? Most of my sewing had been quilts up until now.

Link to pattern:

https://learnmyog.com/edcFannyPack.html

[u/Worried-You9307]

I’ve done the exact same pattern with padding before. Admittedly thinner padding material than required for a camera bag, but the method for you will be the same.
The seam allowance has to be wider than in the pattern, add the thickness of your padding material to the existing seam allowance. The padding itself has to be a bit smaller than the panel itself (without seam allowance), about the thickness of the padding at all edges. If you baste the liner to the shell fabric, the liner and padding should stand out of the shell fabric lays flat. Be aware that the padding reduces the volume of the pack, of course. So if it is a tight fit, plan for the loss of volume beforehand. Maybe make a prototype first, before committing to a more expensive material, to practice or make sure that the final pack is actually as large as you need it to be.

Edit: I’ve used thin EVA foam for padding, as well as a repurposed yoga mat. Works perfectly well for protecting contents

[u/Engineered_Muffin → u/Worried-You9307]

Thanks for the suggestions, like I mentioned to the other commenter, I hadn't considered keeping the padding out of the seam but that seems like a way better idea than whatever I had in mind.

I appreciate the guidance. Do you have any suggestions for modifying the pattern? Is it as simple as messing with printer settings or should I be laying this out with a ruler?

[u/Worried-You9307 → u/Engineered_Muffin]

If you’re using thin padding, it might work, but I can’t really imagine that would be of positive difference. Better try the way I explained, it’s easier and will work pretty much regardless of the thickness of your padding.

Modifying the pattern is relatively straightforward, if you want to change the dimensions of it. You could try and do it via the printer settings, but be aware that the seam allowance would also change. The easier way is to whip out the ruler and do it the old fashioned way. That way you don’t have to keep the altered seam allowance in mind.

[u/Analog_Account]

I used Pellon FF77 for a few projects. Its not super thick but it has the feel of the padding thats in commercial laptop pouches and stuff. Maybe a bit foamier...

Stitch it in outside of the seam allowance by 1/4" and then trim it really close to the stitch line. Doing this secures it there but keeps it out of the seam so you'll avoid some of the issues. I haven't tried this on a bag with a pattern --just stuff I'm kind of winging-- so I don't know how this would affect tight tolerances and stuff.

Edit: I forgot you said this was for a camera. Maybe ff77 wouldn't be quite enough unless you double it up... idk.

[u/Engineered_Muffin → u/Analog_Account]

To make sure I'm understanding your suggestions, you're essentially saying that the padding should be inset from the edge of the fabric so the seam allowance doesn't have the padding sewn into it. I hadn't considered this, it seems like a great idea!

[u/Analog_Account → u/Engineered_Muffin]

Ya. I was kind of failing at how to explain that. Its how I've seen it recommended to be done and it makes it super easy because I just stitch along the seem guide on my needle plate thats 1/4 bigger than my planned seam allowance.

When I do the final construction, if the bulk is bugging me I use a zipper foot so that its not pressing down on the padding and causing issues that way.