I was sent some Chalkola pens by Anuj at Chalkola - here is a link and you can find them on amazon here and here (the other good news is you can get a 15% discount with this code 15OFFSTR). They are loads of fun and work well on non-porous surfaces, like windows....we could have had hours of fun just being daft. I also thought that they would make nice window decorations for parties and with snowflakes in winter etc. The colours are nice and bright, and you can wash them off with water - you get a bit of a chalky residue mixed in the water so I used a second cloth to dry up the water and pick this up as I went.
I don't have a big chalkboard in my kitchen, but I do have a black fridge, so again lots of colourful writing and some pictures.
I wanted to try them out on a scrapbook page, my tip would be that you should use a fixative like hairspray over the top of the chalk before you stick your photos on, as it is chalk it can smudge slightly when you use it on paper...however the colours work beautifully on dark cardstock - some work better than others, like the green, orange and yellow.
I had a play with lots of colourful doodling...there is no patterned paper at all on this page!