Reducing the space between plots in GraphicsGrid?

Question

I am using GraphicsGrid to produce the following figure:

Plot1 = Plot[Exp[-0.03*t], {t, 0, 300}, 
   AxesLabel -> {None, "testing1"}];

GraphicsGrid[{{Plot1}, {Plot1}}]

Is there a way to control how much space is between the two plots?

Answer 1

cvgmt gave you the answer, but I would like to elaborate a bit. When using GraphicsGrid the pain has to do with the AspectRatio if I am not mistaken. Instead you can use Grid. Using Grid is not a golden hammer and it has its downsides from certain points of view; I think that every time I have used it I had to adjust the ImageSize, but I still find it easier to manipulate in most situations. I suggest that you experiment a little bit in each given situation.

Below I am giving 3 alternatives.

Plot1 = Plot[Exp[-0.03*t], {t, 0, 300}, 
   AxesLabel -> {None, "testing1"}];
GraphicsGrid[{{Plot1}, {Plot1}}, Spacings -> 0, 
 AspectRatio -> 1/GoldenRatio]

Plot1 = Plot[Exp[-0.03*t], {t, 0, 300}, 
  AxesLabel -> {None, "testing1"}, ImageSize -> Medium];
Grid[{{Plot1}, {Plot1}}, Spacings -> {0, 0}]

ResourceFunction["PlotGrid"][{{Plot1}, {Plot1}}, Spacings -> 25]