OK, so now you have my creative juices flowing ... some ideas!
* Jumping Jacks .... draw a stick figure of someone doing that
* Jacks ... the game kids play
* Four Jacks of Playing Cards
* Make an acronym of JACK and put on the quilt
* Jack be Nimble (mentioned by PP) ... print out the whole verse on a quilt block
* Union Jack (British flag) ... all straight lines, so easy to emulate)
http://www.diaryofaquilter.com/2010/...know-jack.html
link to a PP pattern
http://free-quilt-patterns.net/paper...UnionJack.html
* Jack in the Box ...
http://www.quilterscache.com/J/JackintheBoxBlock.html
http://piecebynumber.com/hearts.htm
* Jack-O-Lantern ... how did we all forget this one! :) -- link to a PP pattern
http://piecebynumber.com/pastbom/archbom.htm#jack
* Little Jack Horner ... another Nursery Rhyme that could be printed on a block
* Jack and Jill went up the Hill!! -- link to embroidery block
http://sewcraftful.com/how-to/no-16-...e-quilt-block/
* Jack's Delight ... see March BOM
http://www.mooseheadquilters.com/Hom...k_Archive.html
* Jackson Star ... found mention, no pattern yet
http://www.mccallsquilting.com/qb/mc...699/index.html
* Jack's Chain ...
http://www.quilterscache.com/J/JacksChainBlock.html
* Jacks on Six ...
http://quiltville.com/playjacks.shtml
Great name ... Jackson!
Hope you can use some of these ideas! Good Luck!!!