It seems to me that all approaches (file exchange solutions unconsidered) here are lacking the essential step, or finally leading to it via some blurry workarounds.
The figure size needs to equal the paper size and the white margins are gone.
A = hgload('myFigure.fig');
% set desired output size
set(A, 'Units','centimeters')
height = 15;
width = 19;
% the last two parameters of 'Position' define the figure size
set(A, 'Position',[25 5 width height],...
'PaperSize',[width height],...
'PaperPositionMode','auto',...
'InvertHardcopy', 'off',...
'Renderer','painters'... %recommended if there are no alphamaps
);
saveas(A,'printout','pdf')
Will give you a pdf output as your figure appears, in exactly the size you want. If you want to get it even tighter you can combine this solution with the answer of b3.
