Ok I was playing with photoshop and found this
Step 1:
Open your canvas and fill it with the colour of your choice I chose white #FFFFFF.
Step 2:
Pick two colours, so step one is not that needed but that's how I started off so you may want to try it. The colours I used are:
#A10707 And #FFFFFF So a kind of redish colour and white.
Note: It's best to choose one dark colour and one bright colour so they show up.
Step 3:
Filter --> Render --> Clouds
Step 4:
Filter --> Texture --> Craquelure.
That's you done.

Feel free to ad more effects to your liking.
Here's my final result:
