Prewashing Panels Before Making Quilt
 

I have made a couple panel quilts for Quilt of Valor and have prewashed the panel as well as the fabric for the rest of the quilt. I have a pattern that says to not prewash the panel before making the quilt top to make sure the size stays the same. Is prewashing a panel a good idea or bad idea?

Just like prewashing any fabric, it is your choice. If you are using a specific pattern featuring your panel, then I could see where the size might matter in the directions for cutting other pieces. But otherwise, it should not matter at all. I find panels are often very wonky and usually have to dampen them and block them into a proper rectangle.

It depends on the pattern and how much the panel shrinks after washing. It may not shrink at all. As long as the panel is the size the pattern calls for after washing, then it should all work out well. If it shrinks to be smaller than the pattern calls for, then fabric must be added so the rest of the blocks all align as the quilt is assembled.

I would say, if your fabric is prewashed, you'd better prewash the panel. My experience with prewashing a layer cake is that fabric will shrink a bit lengthwise but not discernibly width wise. But I can't picture why it would matter if the panel is a bit shorter than the current size, as long as you note the new measurements and make adjustments accordingly.

if need be you can always wash , press and trim if needed and then add a border to make it the exact size they say it needed. Panels are notorious for shrinking and getting wonky. Still it's fun using them.

I never prewash panels, or pre-cuts, but I prewash everything else. I've had no problems mixing the washed and not washed, but I quilt fairly densely, and that might make a difference.

also try drying on cool or air only, no heat.

I've had panels and cheater cloth skew on me after washing, so I'd vote to not wash until after the top is assembled.