The 'glass method'

Generally, it's for making complex patterns, so you don't have 3-XX layers of MK on top of each other. Basically, you iron down at low temp, the covering edge to the glass. It sticks, but the glass won't allow it to shrink. And it won't stick to the glass, so the glue remains on the covering. You then just iron it on as you would a regular sheet. A bit of care is required..

As for your checkers, this is what I woudl try..

Lay down your base colour. Windex the glass, and squeegee out the windex. Let dry, 24hrs. The MK shoudl them be 'self adhered' to the glass. Then, apply the checker squares, and tack in place with a low temp iron. Or use Trim sovent (But practice first!!!!). Then once happy seal the edges of teh squares with a bit more heat.

Patients & practice are the name of the game!