Back-opening t-shirts
We were making some T-shirts for Camp Wizzy, and received word that some of the campers had big Hair.  With not much spare time before Camp, and only the Camp Director allowed to wear a scoop-neck shirt, we had to switch to Plan B and adapt the Volume 1 T-shirt pattern 110A.
The Camp logos were already ironed on the shirt fabric, and the t-shirt fronts had then been cut out! 

To cut new backs, I printed 2 copies, and marked 1/4" away from the centre back to allow for a centre back lap. I applied Steam-A-Seam to the wrong side of each centre back lap; it's self-adhesive, for a temporary bond, and is not stiff.

with a tear-away stabilizer (onionskin paper) under the fabric, I sewed the shoulder seams with a narrow zigzag stitch, clipped the corners of the seam allowances, and pressed the seams open.

The neck ribbing was cut 7/8" by 3"; I used a lycra-and-cotton ribbing because it has good stretch recovery.  I folded it in half right sides together, and stitched across the ends, with the stabilizer under the fabric.  I trimmed the inner corners of the seam allowance, and turned the band right side out.

With the neckband against the right side of the shirt, and the ends at the lap fold lines, I folded the laps to the right side, and pinned the band to the neck edge at the ends and at the shoulder seams, stretching the ribbing to fit. The ribbing was sewn to the neck edge with a slightly wider zigzag stitch.  I trimmed and graded the seam allowances, and turned the laps to the inside.

I finished the sleeve hems with the Steam-A-Seam; they won't need to be stretched, it looks neat, and there were 20 campers! Next step: sew the side seams, trim the corners and the underarm curve; apply Steam-A-Seam to the lower hem, fold it up and fold the back laps over it, and press to fuse.

Pretty neat!

 Steam the neck-band to a nice curve, with the seam allowances turned down.
And now we're ready for the snaps.  2, I think, above waist level, in case the camper wants to tuck her shirt in.

For a velcro closure, I'd use the soft hook-and-loop tape from tiny Zippers.

Happy camping, dolls!