My resistance to using watercolour paper when tangling is that it seems impossible to find one that is sufficiently smooth plus white (as opposed to cream which does not contrast as well as white with the black pen) at a reasonable price.
Daler-Rowney Langton 300gsm Hot Pressed Extra Smooth
I tend not to use this watercolour paper when I'm watercolouring with inks - stamping & using a damp brush to drag the colour out - as the ink colours seem to lose their vibrancy. I believe this bleaching effect has something to do with the amount/type of size used during watercolour paper manufacture & therefore varies with type & brand.
The Pigma Micron pen is an absolute joy to use on this giving beautiful coverage when filling in solid areas. The Polychromos pencil also blended magnificently with the tortillon.
If it were not for the creamy colour, I would rate this above the W H Smith 220gsm White Card that came out best in my previous testing. It is also more costly & far more difficult to obtain than the W H Smith card.
The 190gsm weight of this paper makes it ideal for using when an image is to be cut out as well as watercoloured. It is therefore the one that I use most frequently, especially as it is extremely economical in price.
When it came to the Pigma Micron pen the coverage when filling in a solid area was very good - not as good as the Langton - but perfectly good enough. The Polychromos pencil also blended smoothly but again the Langton gave the superior result.
The colour is creamy so once more I would prefer to use the W H Smith 220gsm White Card for tangling, especially as the latter is so economical.
W H Smith 300gsm Watercolour Paper
This was my first encounter with watercolour paper, before I knew very much about how differently various paper surfaces respond to inks & pens etc... I tend to use it only for making colour charts of media which require the application of water for use.
This gave very good coverage when filling in a solid area with the Pigma Micron pen but only allowed very patchy blending of the Polychromos pencil.
The colour is predictably creamy but I would not use this for tangling anyway. I shall use up my supply for making colour charts but doubt that I will buy any more of it.
The W H Smith 220gsm White Card remains my favourite for tangling, especially if I am going to layer it onto another piece of cardstock. If I want more weight to my project without another layer I would use the Langton - the price differential will probably become immaterial when more than one layer is brought into the equation & I may find that in time I shall prefer the subtler contrast against the black provided by the creamy colour.