How do i use Grainclips that is too short

I have some Grainclips similar to Cinegrain or Rgrain that i want to use as overlsy on my films but they are too short to fit the clips i have.

Can i in some way make them longer so they just start over again and again too make them fit?

I have tried to slow them down with quite good result, then they play for a longer time but then they are not really the same clips. The best thing would be to make some kind of loop that just plsys the same grain over and over and in that way make the grain clip as long as i want.

I guess there must be a solution to this because how should the grain making companies know how long our film clips are. They make a grainclip and then we must be able to apply it to as long clips as we have i suppose but how?

It's just grain overlays, so why don't you just repeat the overlay clips and add transitions between them?

That would be ok as long as it fits with my film clips but when i have a film clip that is 20 seconds and a grain clip that is only 10 seconds i get a glitch in the filmclip when i overlay two grainclips on it.

It seems that the different grain plates out there is often only 10 seconds or so, so i guess there must be a way to repeat them forever if you want to add grain to a longer film clip.

Otherwise it is the grain makers that tells us how long our film clips can/shall be...

Professional grain plates such as RGrain loop at 1 minute, so it's very easy to repeat the same plate over your footage until your repeated plates cover your entire edit. The plates will loop without any glithces.

If you have non-looping plates just put a transition between the repeated plates to mask any glitches.

You shouldn't see a glitch or a jump when you have the grain next to each other. But give it a try with a transition... or reverse the second grain and remove the first frame.
Can't really judge much on it unless I see the grain clips.

Ok, i will have to experiment some more with putting clips beside eatch other without getting a glitch.