I have been using Poser for many years (since version 2) but never really thought about this and have not seen anyone ask in all this time:

If I enlarge a Template to make a texture; do I get increased resolution in the rendered output?
I mean: lets say I buy a model, the creator mapped it and supplied UV Maps at 900x900, lets say it is a T-Shirt and I want to make my own texture with words.
900x900 in today's terms is rather small and text or intricate designs will only have so much quality in the rendered output: So, if I open up the supplied 900x900 template and Enlarged it to 4000x4000 and make my texture (saving as 4000x4000) does Poser 'project' that larger texture onto the model or does the render engine shrink it back down to 900x900 for rendering due to the size the .OBJ was originally mapped.

Second: if the render engine does shrink it back down to 900x900 then would Remapping the .OBJ at 4000x4000 and swapping it out in the Geometry folder be the solution?

I know, dumb question but just wondering.....

Use something like the free uvmapper, and extract the template from the obj and save it at 4000x4000. Then the template will be right and textures made using that template will look the way you intend.

Scaling down is better than scaling up.  It would seem more reasonable to create a higher-resolution template for the purpose of zooming in and out on your work as mentioned.  Maybe consider working with a .PNG image format that tolerates scaling better than .JPG.

You can scale the template up with no problem in any 2d editor. I've done it. Just do it before you start editing unless you have a magic enlarger that will scale up without a loss in quality.

I believe Poser projects the image onto to the UV map not the obj, the  effective texture resolution applied to the obj is dependant on how the UV space is mapped to the obj (think this is called  texel density). For example if the tee shirt maps the full 0-1 UV space then increasing the texture size to 4K should increase the texture on the tee-shirt obj to 4K also. If the tee-shirt is mapped to 0.1 x 0.1 UV space the actual texture resolution on the tee-shirt will be much less (sorry bad at math). If using Firefly there is an additional setting (IIRC "min shading rate") that will also determine the effective texture resolution as this is used to "dice up" the model before rendering. 

@ironsoul; I think maybe that answers my question.

I am not talking about enlarging a texture to edit and then reducing it to apply in Poser.
What I am wondering is: If I enlarge the Template, then paint my texture to to and Save it at the larger size...does the render engine render my larger template or does it (behind the scene) reduce it back down to the smaller size that the object file was originally mapped at?

@hborre; pretty much what I have started doing.
I was just wondering if:
1) could I save some work and just enlarge the existing template file, paint it, save it as my larger file and use it - or would the render engine just reduce it back down to render?
2) when I do re-map (not really "re-map" but just run it through UVMapper and save as a larger template) do I need to Save the OJB in place of the original for the render engine to use my newly sized map....or would the engine look at the obj and look at my larger texture and say "Hey, this map is too large, I will shrink it down and render it"?

Poser does not scale anything. A .jpg or .png image bears no memory of its history so Poser would have no information to go by. Poser expects the u and v coordinates to have values between 0 and 1. If the value provided is outside that range, it ignores the integer part. u = 3.234 is taken as u=0.234. If your texture is saved as 4000x4000 it simply takes the rgb value of the  936th. pixel at the given (v) row.    

When texturing always work with the highest resolution possible. You can resize your UV template to 4000 if you don't have one that's 4000 but you will run into problems when you have to texture around the edges. Use the upscaled UV template only to give you an idea how big the text needs to be and where on the T-shirt is going to be placed... then insert your text.

Just to explain my post - increasing texture size will increase the amount of detail but when working with older models where PC memory resource was more of an issue the UV map may be stretched to allow all objs in the model to fit on the same texture map. This could lead to less than expected improvements. Attempt at demo of how UV mapping impacts detail below - both images rendered using same obj and image but one of right has a stretched UV map - where the UV grid is narrow the render engine stretches the pixels across a wider section of the obj causing a loss of detail. Stretched UV map shown below also. It should be possible to exploit this to increase detail on parts of the obj where detail is at the expense of areas that are unseen.

Practical example - there is a limited scope to increase detail on breast plate due to UV layout. I could increase to an 8K but the increase in render detail would not be worth the increase in RAM required to render.  lf your own the model then using UV mapper or blender to make full use of UV space is an option. 

I think the confusion here is in the terms 'UV' vs 'template' vs 'texture.
where:
UV is the coded map of the object as it presents itself to the render engine
Template is the 'template' of the UV mapping, used in graphic apps to paint on
Texture is the painted template of the uv mapped object.

Now, in UVMapper one is asked "What size to save out the TEMPLATE" and usually has a default of 520x520 (?) but can be changed to 'whatever' and not even need be square.
The question here is again:
IF I saved out the TEMPLATE at default 520x520 but then in Photoshop enlarged it to 4000x4000 and painted a Texture on it. Save the Texture at the 4000x4000
One can paint much more detail on a 4000x sheet of paper then on a 520x - but both being applied onto the SAME Obj with the same original UV mapping.

I think FVerbaas and ironsoul answered the question.
Also the T-shirt I was speaking about does render out much better with the larger Texture then had I painted onto the original smaller map.
No "stretching" involved....sorry, I did not understand that explanation at all but have seen ill effects if say the Original map was Not square (say 1024x762) and I RESIZE the TEMPLATE (or texture) into a 1024x1024 and paint on it....IF I then apply that texture to the object it 'stretches' the texture UNLESS I run the object file back through the mapper and save out a 'squared' UV map (ie Template) and replace the original model with the newly mapped one.....

Anyway: resizing the TEMPLATE did allow me the results I was looking for - thanks all

This is how your UV template should look:

and this is how it looks after it was enlarged:

Now, can you tell me why all your seams are going to have a black fade to it?

... and what exactly marks the edge of your template, the edge of your object that Poser has to wrap using your texture? Remember... it's zeroes and ones!

And this is where Poser stops applying the texture to your object because that's where the object ends.

Use something like the free uvmapper, and extract the template from the obj and save it at 4000x4000. Then the template will be right and textures made using that template will look the way you intend.

There's also the issue of graphic file type, as some up-scale much better than others, pixelate less...

FWIW, using a 'UV UnWrap' program is often exasperating, as may prove very difficult to match existing mapped texture. Some are 'accessible', others are variously 'optimised', different sections docked like 'Tetris' to minimise 'empty' space. Worse, zones may be 'smudge painted', confounding your attempts to identify detail...

This is less a problem for 'native' Poser items than 'ports': eg Identifying an imported but minimally grouped OBJ or FBX vehicle's lights, mirrors, glazing etc so you can mask physical properties may be trivial or require an iterative hunt. A 'binary chop' of such mapped textures will eventually find the needful, too often tucked away obscurely...

There's no issue with enlarging the template first. Yeah, you get some blurred lines, but that can easily be worked around. You use the outside of the lines on the edge of the template and the center of the ones in the middle

here is a skirt that was textured with the original temple of 500 and one enlarged in Paintshop Pro to 2048. The second is much clearer. It's more noticeable if you view the image at full size.

and here, you can see a closeup of the island edges to show that there isn't any of the template background peeking through at the edges.

There's no issue with enlarging the template first. Yeah, you get some blurred lines, but that can easily be worked around. You use the outside of the lines on the edge of the template and the center of the ones in the middle

here is a skirt that was textured with the original temple of 500 and one enlarged in Paintshop Pro to 2048. The second is much clearer. It's more noticeable if you view the image at full size.

and here, you can see a closeup of the island edges to show that there isn't any of the template background peeking through at the edges.

One other point to consider is the final render size and how many of the pixels in that final render are going to be used for your object/texture.  In RedPhantom's example above the higher texture is visible in the output as most of the screen is filled with just that image.  On the other hand, if those skirts were 20 feet back from the camera and only occupied an area of 100x130 pixels in size then both would be scaled downwards and little to no detail would be readily visible.  Think about a leaf if you did a close up of that leaf then a 2K image would be in order to convey the full details present.  However, if you rendered a forest and the trees had that texture on each leaf and there were thousands of leaves then you would get maybe 2 pixels to convey the leaf and all the detail in that 2K image would be compressed down to 2 pixels.  So it comes down to a balancing act between visible detail and render resources.  

As far as UV to image maps, A UV map (Normally) is in the range of 0-1 both up & down and left to right.  A value of .5, .5 in the UV map would be dead center of the image map.  If the image map was 500x500 then the center would be 250,250.  If the map was 2000x2000 then the center would be 1000.  The center point is the same just how many pixels there are to work with.  If the 500 image map was used to make an image of 2000 pixels then each pixel would have to used 16 times (4 times each direction).  However, if the 2000 image map was used then it would be a 1-1 rendering and look the sharpest.