Thought I should share this with you,
got this idea today and had to try it out, worked like a charm!
Basically you use your vacuum cleaner and a very simple construction to build a vacuum table that will hold the stencils in place while you are working with the paste.
Eliminates the risk of smearing out the paste, especially on large PCBs with small pitch where it might be difficult to apply all the paste in one go!
Obviously it only works if you have a few vias or mounting holes…
Looks like a good idea, but I think I would prefer somthing like a reverse air hockey table. Use something with a smooth surface and then drill a bunch of small holes on a fairly small grid size. Then use thick plastic sheets to create a four-sided funnel of some kind to attach to the bottom. Attach the vaccum to the funnel.
This way, you are not limited to the board size and it would even help hold the stencil down if it overhung the board by several inches on all sides.
Reverse the airflow and have one kickass mini air hockey rink 
