The 36 pack of Colorito Thin pens has a thin 2.9mm fibre tip which is durable enough to stand up to hard pressure without disappearing inside the pen. The ink is water-based, so is washable from fabrics & skin. The pens are also non-toxic and have a vented cap for safety. The barrel is narrow and coloured in the same shade as the ink inside.
The pack of 24 Colorito Maxi pens comes with a FREE pack of 12 to keep as spares or supplement your collection.
Again, these pens are water-based, do not bleed through most paper, are washable and non-toxic. They have a broad 6mm tip which tapers to a 2mm line, so they can be used to colour larger areas quickly and smaller areas when angling the tip down.
Physically, the pens have a thick rounded barrel which is coloured in the same shade as their ink, and they also have a vented cap which prevents choking if swallowed.
The strong and durable fibre nib stands up to heavy pressure and is designed to be long lasting. The larger box has 24 different colours with no duplicates, including several unusual shades of red/pink. The ink is vibrant and lays down smoothly on the paper, but being water-based, it can appear streaky on larger areas.
Overall I think these pens are really good value for money to say you're getting 36 for the price of 24 :)
Here are some pictures I coloured with both sets of pens.