Problem with pasting paper

[Stoverpd]

Hello,
I'm a plastician artist, and I decided to make myself my frames. So I've invested in purchase professional equipments.
I've made a frame with floating paper behind a museum glass.
The paper is pasted on a foam board with flexible strips made with Gummed paper to safeguard the original artwork and pasted by moistening the
gummed paper (photo of product linked)
I used 300g Arches paper fine grain, to create my artwork.
The result is not correct, traces of pasting paper is apparent by transparency (photos linked)

do you have advice to give me to fix this and not reproduce these defects?

Thank you so much

[JFeig]

It appears that way too much water(moisture) was used when applying the hinges to the art. In addition to using too wet hinging, you might have not applied a blotter paper, to absorb the excess water, behind the hinge and under weights when allowing them to dry.

[Justintime]

I would also suggest increasing the size of your foamboard to 10-15mm smaller all round than the size of the work. I use a small flat paint brush to apply the water in repeated strokes which helps activate the gum without saturating the paper and gentle burnishing helps to remove any excess water.

[prospero]

Did you 'feather' the tabs? That is, tear them to create an irregular edge and tease ot the fibres.
Otherwise you have a hard edge which will be apparent from the front.

But honestly I would mount the entire sheet on a thick 100% rag board, or better still two layers of board.
The board will need to be slightly smaller than the paper if you want the deckle edge to show.
Do this before you execute the work. Expecting a sheet of floated heavy watercolour paper to remain
dead flat is an exercise in extreme optimism.

* Before anyone says mounting the paper is permanently altering the artwork from it's original state, you are the
artist and if you do it (or get someone to do it on your behalf) then it is the original state.

[Justintime]

I think showing us an example of your hinging technique will help us offer advice.