# Bottom-Up Stack Bottom-up stacks can be used to display stacks of elements which should move up as more are added. This concept is similar to messages received in a chat window. Gum layout can be used to produce this type of stack. {% hint style="info" %} This example shows a bottom-up stack (vertical) but the same approach could be used to create a right-aligned stack. {% endhint %} Items in a bottom-up stack need a parent Container. This Container could be an instance of a Container or a component since components usually have their `Base Type` set to Container. For this example we'll use a container.

This container to stack needs the following variables set: * `Children Layout` set to `Top to Bottom Stack` so all children stack vertically

* `Height Units` set to `Relative to Children` so the container resizes itself as more children are added

* `Height` set to `0` so the effective height of the container is based purely on its children

* `Stack Spacing` set to `2` (optional) to add spacing between each child

Now children of the Container stack vertically. This concept works for any type of child, but we'll use ColoredRectangles for this example. Add a few instances to the Container and they stack vertically.

ColoredRectangle instances stacking vertically in a container

Finally we can have the stack grow up instead of down. To do this, change the following variables on the parent container: * `Y Origin` set to `Bottom`

* `Y Units` set to `Pixels from Bottom`

Now as new children are added, the parent stack grows and all items shift up.