How do you quilt something when you don't want to disturb the pattern of the top?
 

I am in the planning stages for a new quilt for 5yr old grandson. http://cuttopieces.blogspot.com/2012...ilt-along.html I have just ordered all the materials needed and fabric, but just realized that I have no idea of how to quilt the layers. :( Since each piece will be a 1" finished square, SITD isn't an option. And using any kind of colored thread will disrupt the pattern of the quilt top. Is a clear nylon thread appropriate for kids? How durable is nylon thread? What kind is best? A clear thread would let me do cross hatching. I know I am way ahead of myself, but daughter is buying all the supplies, so I try to get everything before I start.

Some monofilament can be scratchy, so do some testing first.
You could also SITD around the color block areas, like all around the contiguous black area etc. If you are worried about the stitching showing in then adjoining color, you could stitch 1/4" or 1/8" in from the seam.
You can also do cross hatching or stippling with matching thread, changing it from area to area. A 5 year old is going to love anything you do with Mario!

You still can ditch this by outlining the character's features with matching thread doing FMQ.

Nylon thread is a mess. It is stiff and hard to use. If you decide to use something similar, look at Superior a Threads polyester transparent thread. I personally would use a batting that doesn't need a lot of quilting and then outline the design elements.

Pam

First, I would not consider a batting that does not require a reasonable amount of quilting ( fist space) because this is for a kiddo, thus going to be "used" a lot and washed frequently as a result. As far as quilting it...large meander in a maybe flesh colored thread...?????? Again, going to a kiddo....not just for show..will get a lot of GO!!!!!!

What a great quilt!

I would stitch to outline the characters and SITD the sashing. I would think that that would be plenty, depending on how large the blocks are.

I'd quilt a test block first if you have enough fabric using a clear polyester thread. I'd also machine quilt it. Hope you post a picture of it when it is done!

Today's monofilament (both nylon and polyester) threads are not the "fishing line" of a decade ago. Some are as fine as a human hair and yes virtually transparent. I showed my monofilament to a client who used to be a surgical nurse and she said it looked like the suturing material they used when they had to do surgery on eyes! So that should give you a good indication of how fine it is and it is not stiff and pokey anymore either. Another option for thread is something super fine like silk (very expensive) or Invisifil polyester by Wonderfil threads. Both are 100 weight and sink right down into the fabric and batting leaving nothing but texture behind. They tend to blend in and reflect whatever color they are laying on so if you used a soft gray it should mix right in with every color on the quilt.

Because this quilt is for a 5 year old and has all the potential of becoming a favorite and "roughly" loved quilt I would opt for an all over meander that is fairly dense. It will help the quilt survive all the inevitable washings and it won't detract from the design at all.