The rocks in the crib

In almost all the cribs that reproduce landscapes there are rocks.

In a nativity scene, rock means small pebbles or rocky walls of a much larger size. There are several ways to reproduce rocky landscapes the easiest is to collect in nature, rock fragments of various sizes, or stones of any shape and insert them into our work. To proceed artificially instead, we must equip ourselves with plaster, jute, foam rubber, and polystyrene and work them with tools such as the very useful spatulas.

Once shaped our rocky system we must complete with the coloring.

As far as coloring is concerned, I have reserved a large paragraph where I explain everything in detail, but if you want to have visual and explanatory explanations I recommend my Video Course on DVD.

In some images below it is possible to view an example of soil produced with jute and foam rubber. The rocks that characterize the setting are therefore those that are made by hand by the crib that, with its own creativity, can give life to unique shapes and can reproduce rocky environments typical of certain natural contexts. The first step to make a rock is the BASE.

Its structure is made with different materials for example, polystyrene for packaging, wood, cardboard.

materiali per il presepe

Having obtained the base with the desired rock form, it is necessary to proceed with the jute covering.

If you have created a very large or winding base, support the jute with a metal mesh.

Available at any hardware store. On the jute, cast the plaster with a denser consistency, to facilitate the grip on the fabric.

Apply with a spatula a quantity of thick chalk that will be worked to completely cover the polystyrene base.

Polystyrene can be placed in layers, vertically or as desired depending on the rocks to be built, calcareous sedimentary or other.

The preparation of the plaster is very simple to implement; just put water and gypsum in a bowl of water until it tends to surface on the surface of the water. Be careful not to mix the plaster ahead of time, I suggest you mix it when you start work to prevent it from hardening immediately.

Do not prepare excessive quantities of gypsum because it is fast drying and does not allow much time for modeling, normally one small portion is processed at a time.

preparazione gesso per presepe

To avoid the formation of lumps the plaster is put in the rain water (dusted), the more you add it and the greater its consistency.

In the case of rocks, do not exceed in quantity. Always remember that it should be left to rest in the water without stirring for a few minutes so that it gets completely wet and does not harden quickly.

When you decide to start work, you start taking a bit of plaster at a time with a spatula without mixing. The plaster settles on the surface, on polystyrene with a spatula.

Apply the plaster gently and arrange it evenly, without neglecting any fissure.

On the jute the plaster must have a more liquid consistency, therefore during its formation it will be necessary to increase the doses of water. To learn about the various chalk techniques, view detailed explanations on the construction of the rocks, I recommend my VIDEOCORSO IN DVD.

Place and fix the polystyrene and jute on the structure so as to have a fairly solid base.

The base must be sealed with vinyl glue, but for greater safety you can use nails, toothpicks or wire.

Begin to prepare the plaster, a little at a time.

It must first be spread liquid and then more and more dense, so as to create reliefs, stones and cracks typical of the rock.

The trick is to first fix the parts that have been assembled with a little plaster, and then wait before continuing so that the structure, after drying, is firmer and easier to work with.

Later use small slats, as they are called in slang, typically those used for restoration and fine arts, to create engravings at will, incisions can be vertical or horizontal.

To get more realistic effects, use the chalk residues and apply them, the more you work the plaster the more everything will be real. To learn all the tricks to get realistic and striking beauty effects in a simple way, I recommend buying my DVD VIDEOs.

All this is necessary to have a solid coverage of the support and at the same time to recreate those movements and unevenness typical of rocky landscapes.

Before finishing, use dry plaster on the surface to remove the moisture from the plaster and create the crumbling soil effect. A strainer or strainer can be used to apply the chalk powder.

The jute can be immersed in very liquid plaster before being placed on the structure and then shaped, but this operation, although it guarantees that the weft is impregnated, is not recommended because, in addition to causing dirt and dripping around the work, it needs further revision with more compact plaster that goes to eliminate the texture of the canvas that resurfaces on the surface.

Once the plaster has been laid down, it is necessary to wait for it to dry, before it is completely dry it is still possible to modify and mold some parts using any sharp object. The techniques and strategies to be used in these steps are explained in detail in my DVD VIDEOs.

gesso per presepe come utilizzarlo

First I mentioned another material with which it is possible to build rocks for our crib, or foam rubber.

This material must necessarily be chopped to be used, to do this we can use our hard-working hands, or use an old blender.

The pieces obtained are immersed in the plaster, deprived of excess plaster and applied on a support surface.

With the thickest plaster all the holes that are created between the various pieces of foam must be covered, with the help of a spatula you can get a wrinkled surface.

utilizzo del gesso nei presepi

Apply dry plaster powder to absorb excess moisture and simulate small rocks and the ground

Dusting on dry chalk rocks absorbs moisture, and offers a realistic result at work. At the end of drying, the surface of the foam rubber should be broken with the aid of any object or the same hands, crushing it and immediately releasing it, so as to create a particular effect of cracks.

Remember that the incisions on the plaster can be made in the course of drying also in several phases, in such a way that the plaster is incised horizontally or vertically when it tends to harden.

Dusting with dry chalk in powder to absorb excess moisture and simulate small rocks and soil once dry, creating cracks and carvings of different nature during hardening, which will guarantee a particular and realistic effect. For more clarifications and easy and detailed visual and audio explanations, I recommend buying my DVD VIDEOs.

In order to obtain a characteristic appearance we must wait for the coloring.

In the previous photo an example of soil this time made directly on polystyrene, appropriately scratched to make the plaster adhere and with the addition of pebbles also directly into the plaster mixture.

Coloring of the rocades used for cribs

This phase is simple to perform, you just have to pay close attention to the shades you are going to apply.

For greater security and to acquire all the tricks to create perfect tones I recommend my VIDEO VIDEO COURSE ON DVD

colorazione rocce per presepi

The natural earths are the most suitable for the coloring of the rocks, because they are soluble in water, they take on particular nuances and are quite cheap.

Here are some basic colors to use:

TERRA DI SIENA NATURALE
TERRA DI SIENA BURNED OCRA GIALLO
OCRA DUNKEL BRUNO KASSEL OR DARK BROWN BLACK LIVES IN GERMANY
BLACK ROME
RED EARTH
YELLOW LAND
LAND OF NATURAL AND BURNED SHADOW
VERY DIFFERENT GREEN

Get a container of water, rabbit glue to aggregate the soil and to prevent fading. Also for the glazes read the specific lesson on coloring.

Take a not too small brush and wet it abundantly in colored water or simply in water without color and still wet, pass it on the plate or in the palette of the previously prepared color.

colorare le rocce in un presepe

Spread the color on the surface with plenty of water, using different colors every time to create natural shades of the rock.

I do not recommend the use of too strong colors, it is necessary to bring out the veins of the plaster, a color that is too dense could limit work performance.

The brush should be dipped in different colors, mixing them together on the surface

. Over time you will know the amount of water to use for optimal coloring and rabbit glue as an aggregator.

The green is applied in the veins of the rock in different shades and mixed with the base of color used previously, in order to create the typical humidity effect of some rocks.

Also in this case the nuance must be very delicate.

colorazione rocce presepi

I advise you to collect images, photos of rocks in order to have a precise inspiration and get a color as close as possible to reality.

Here are the characteristics of the various types of rocks:

CALCAREE ROCKS: of clear gradation, tending to whitish
SEDIMENTARY ROCKS: reddish in color because they contain a large amount of iron
BASALTIC ROCKS: they are those with a darker color, tending to gray.

The color on the gray is suitable for close-ups, but brown can also be used.

The chiaroscuro technique is not recommended, since the use of the important quantity of water allows obtaining natural and realistic nuances. The brush must always be very wet and practically soaked with color.

A dish is used because it manages to keep the water from the brush.

To use the colors, you have to start from the darker shades and then finish with the lighter ones, the passage of the shades must be gradual and carried out in several moments, in order to have a control over the coloring obtained. Do you want to go deep into the color coloring? In my DVD VIDEO COURSE you will find the answer to all your questions.

I remember once again that the color must be extremely liquid in order to penetrate well into the cracks that are created in the incision of the plaster.

The brush should be continually wet in the water.

If you should miss anything during coloring, you can wash the surface with water using the same brush, to obtain an optimal result, use natural colors such as earth or pigments.

To obtain the moist effect, the oil color is dissolved, for example brown with a hint of blue or Sienna, with 50% of essence of turpentine and linseed oil, and pass it where you want, or with powdered pigments together water-based varnish with a glossy effect.

The final result will be very close to our starting mental project.

Consider that the color penetrates more into the cracks, giving this particular effect to the rocks. If polystyrene or foam rubber is used to make large rocks, the individual polystyrene pieces must be assembled together with nails and then worked with plaster. using this technique we work the rock trying to simulate a very common type which is basalt, which has the characteristic, the surface is smoother.

These parts are worked with the same characteristics that were previously highlighted and therefore, covering the cracks and holes, trying to naturally model the rock, with the help of a careful observation of nature. However, it is considered that already the positioning of pieces of polystyrene of suitable shape and sizes greatly help the following work with plaster.

Here you can observe a rocky wall, worked with very large pieces of foam rubber, about 50 cm, assembled, positioned and tied on a structure of wine cellars.

Here the plaster was applied directly on the foam rubber, now fixed to the structure, and the holes and spaces were covered with other applications of foam rubber soaked in plaster.

For innovative ideas and techniques never before described, I recommend my VIDEOCORSO IN DVD, an unmissable opportunity not to be missed to become experts in the field.

The rocks for crib made with polystyrene and polystyrene

To make rocks, you can use all the residues we have obtained from the cutting and processing of polystyrene or polystyrene houses, bound together with different techniques and adhesives.

The residues must be positioned in such a way as to create a shape that comes close to the type of rock we want to create. In nature there are different types of rocks, their conformation depends on the environment in which they are found.

Based on the crib we want to make, we will select the most suitable rock, keeping in mind the colors and shapes.

LE ROCCE CON POLISTIRENE E POLISTIROLO

With polystyrene it is possible to make rocks of various kinds. On a woody or polystyrene base the rocky wall we want to reproduce is welded.

The pieces of polysitrene are assembled and fixed with the use of vinyl glue or hot glue. If you use hot glue, pay attention to its temperature, because if it is too high it can seriously affect the work. As we proceed to add more pieces of this material, we begin to decide on the shape of the wall using nails or a toothpick to make the added parts stick together.

After fixing the polystyrene to the base, we can proceed with the incision, which can be done with a welder, a cutter or a large blade.

Or you can create blocks of rock with polystyrene, if we have it, by cutting them with a cutter, beating them with a hammer, cutting it with the saw, all to create a natural movement of the rock

The pieces are glued with glue or dense plaster to make them stick to the base surface. To create the cracks in the rock, the holes and the protruding parts, you can use all the residues and glue them or simply stop them to make the construction as natural as possible.

To get a realistic and rough effect, use a wire brush and tap the rock face. Subsequently, it is passed to mix a bit of chalk with the addition of fine sand, of the natural earth obtaining a really rough mixture., I recommend this step only if we have to make very grainy and friable rocks. In general, it is advisable to use gypsum obtained with the Catalan technique, a more liquid consistency, rest time of at least ten minutes.

The preparation of the plaster, as usual, must be done wisely so that it takes on a consistency that can be worked on the wall.

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rocce presepe

The processing proceeds with the spatula, trying to shape the surface in order to reproduce our initial project.

If at times, pieces of plaster should come off, do not worry, we can later add a few pieces of chalk with a brush or spatula other plaster, or if you are in possession of very compact polystyrene we can remedy by using it properly.

With a dry brush we can take dry plaster and, with small strokes, spread it gently on the surface, in this way, we will be able to dry the residual moisture and have a crumbling rock effect.

effetto roccia sgretolabile

Rocks made with tree bark or cork

To simulate particular rocky walls we can resort to the use of tree barks such as maple, pine. Barks can be found in nature, we can harvest them in the woods when they naturally fall from a tree.

When pieces are available, they must be placed in the crib to simulate rocks or, mountain peaks with the most particular pieces. These are inserted by gluing them with plaster and stuccoing them to hide the addition, you can also use fixing screws to save time.

rocce con corteccia di alberi o sughero

The fillings and the surface of the material take place with the mixture that we have illustrated above. Let yourself be guided by the imagination to insert these elements harmoniously. Work with Catalan plaster on polystyrene to create an artificial rock, using a spatula.

The plaster will have to be worked to make it similar to a rock, for the remaining part a dense slurry is used, obtained with the mixture of plaster, soil, coffee, even very rough sand. This dough is used to fill the rocks between them. The most liquid and watery part of the plaster can be distributed on the surface of the bark to make the color adhere better.

Here is an illustration of the progress of the structure with the necessary fillings to cover the joints and obtain a more homogeneous result. the illustrated technique is a mixed technique, because it involves the use of several elements, including bark, cork, polystyrene, foam rubber and molded rocks.

This is a long-lasting work for this reason, the use of Catalan plaster is preferred, which offers the possibility of modeling the structure to your liking.

The bark helps a lot because it is light and already has the roughness characteristics that make it suitable for the job. It is important to position the structure in the crib to check proportions and dimensions.

Other examples of mixed plaster and bark. The same to make the color adhere they need a very light plaster veil.

roccia mista gesso e corteccia

From the photos it is possible to observe the assemblage of the pieces of bark based on the work we have to carry out, especially with regard to mountains and hills that are in the background. Therefore it is necessary to proportion the parts so as to render the whole homogeneous.

The plaster used to plaster the various parts, when we are in the background, must be of the Catalan type, that is soft and left to rest in order to be malleable for the incision work that exists and is necessary to make the work harmonious.

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Rocks made with molds

For this technique it is necessary to provide us with real rocks that will be the model for the molds. Very comfortable are the types found in DIY stores used for exterior wall cladding.

Of course the natural rocks that nature offers us are very good, indeed it is absolutely necessary to have more than one type to be able to indulge oneself with one’s own imagination.

To create a mold it is necessary to have mastic, the one used to insulate the windows, this ductile material is laid, with a certain pressure on the portion of rock of which you want to create the mold.

For innovative ideas and techniques never before described, I recommend my VIDEOCORSO IN DVD, an unmissable opportunity not to be missed to become experts in the field.

rocce con gli stampi

Once the negative is obtained, we proceed with the preparation of the dense plaster, spreading it inside only on the surface with a minimum thickness without loading too much with the quantity of the same.

What you get is a portion of rock that can be used by cutting it and inserting it into the rock wall, onto the ground, fixing it with plaster or ready-to-use cement, if necessary.

The result will be very close to reality, above all if we succeed in making the whole of the structure homogeneous.

The molds are made in the case of numerous replicas of the object, on the market ready-made molds for use in silicone rubber are available.

The shape of the rock obtained is inserted into the crib also using polyurethane foam to glue the various pieces and plastering the rocks between them, this method is recommended in case of very large dimensions.

When we assemble the rocks we use a so-called “rubbish”, as the Spaniards call it, composed of gypsum, which acts as an aggregator in sufficient quantity, of the earth, sand, residues of plaster processing and what your imagination recommends.

The dough should be thick and very grainy. The bonding parts, where there are holes, can be filled with appropriately cut polystyrene to simulate rocks.

Let’s take an example of realization, we take real rocks that will serve as a model and plasticine or soft clay.

Subsequently the rock is extracted from the mold and an attempt is made to place the mold in a position that also reproduces the volume of the rock in question.

We prepare slightly thick normal plaster which will be used to make the various reproductions adhere to the more vertical parts, then sprinkle the interior trying to fill only the mold of the desired thickness. It is not necessary to fill it completely.

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posizionamento rocce sul presepe

Here is an example of positioning on the crib.

In the photo the effect of the molded rocks that we have created after the grouting phase with the so-called “rubbish” and after the application of the dark background preparatory to the final coloring

Some phases of the coloring and the final effect on the rocky structure at this point remains nothing but to add vegetation.

Make the soil in the crib

The base of the crib is usually covered with polystyrene or polystyrene. The terrain of the crib is subject to strict linear perspective laws, so it will necessarily have to be sloping

terreno nel presepe

Here are several ways to create a plot once the base is created.

The first method is to use jute or medical gauze, covering it with plaster, or you can opt for direct modeling on polystyrene or polystyrene. The land will never be flat but will have bumps, pebbles, holes and anything else we want.

Once the base of the ground has been created, with polystyrene, we can add pieces where it seems more appropriate, in order to create natural movement.

Then we prepare small pieces of foam rubber, polystyrene or polystyrene to one side. We make a little chalk with the technique seen above and begin to spread it on the surface, we add to the mixture of coffee, rather than sand or residues of the plaster work done previously.

You can also have appropriately minced dry residues and ashes for example or soil to be mixed dry and sprinkle on the parts where we spread the gypsum before it dries so that this mixture adheres to the surface and simulates the movement of the land.

In essence, the plaster must be as lumpy as possible to simulate real ground. Dip the small pieces of polystyrene or foam rubber in the plaster, squeezing them gently, and place them in the crib.

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With a dry brush dipped in gypsum powder, sprinkle some parts with small strokes to distribute it so as to give the typical effect of small stones. We also create potholes and other defects. We use the spatula to change the shape of the rocks when the plaster begins to harden.

An example illustrating part of a crib where the soil is created

The plaster must be dense even when prepared.

The aforementioned material is added to rain by creating a slight pressure to make it adhere to the still wet plaster.

For innovative ideas and techniques never before described, I recommend my VIDEOCORSO IN DVD, an unmissable opportunity not to be missed to become experts in the field.

In the photo the pressure is exerted with one hand to make the compound adhere to the plaster still soft enough to accommodate these residues.

 

Once everything is dried, the residues that have not adhered can be eliminated. If desired with other liquid plaster, wetting the surface it is possible to apply other material where needed with subsequent applications

Finally we move on to the positioning of the vegetation and also wanting dry soil mixed with earth, to fix it we can use vaporized rabbit glue or spray glue.

Make a large cave in a crib

To make a very large cave, use polystyrene as a base, which will be used to hold mixed concrete. gypsum and residues of previous work and any pebbles.

Everything must be thrown vigorously on the polystyrene walls, not before having affixed to these last, random pieces to give thickness to the arches or to create natural protuberances.

Instead of cement it is preferable to use tile adhesive or ready-to-use plaster because they have more graininess and allow greater adherence on the walls.

From the previous photo you can see the pebbles, remnants of the previous minced plaster work, inserted into the wall.

The photo on the side shows the cave colored with the background color.

Also in this case the game of chiaroscuro is of fundamental importance to create particular and suggestive effects. For innovative ideas and techniques never before described, I recommend my VIDEOCORSO IN DVD, an unmissable opportunity not to be missed to become experts in the field.

Various types of rock in the crib

Here are a series of examples of rocks, placed on different levels of the crib.

Here a mixed technique with chalk and natural elements must be used. Use natural barks, such as larch, pine, holm oak, cork. These elements were inserted into the structure with screws and glue vinavil or stucco to make them adhere to the base. The plaster must be prepared with the Catalan technique already seen in previous lessons. This allows greater freedom and processing time.

The incisions of the rock that are made with awls, diggers and spatulas must respect the rules of both diminutive and definitive perspective. As it moves away from the first floor we have to make less obvious incisions and create softer, more linear movements. In this case we use steel brushes which, when properly used, perfectly simulate the movements of mountains and rocks in the distance.

roccia presepe

Example of processing a wall in which the various parts are mixed.

If we want to create more jagged rocks we can also use gypsum residues that are glued to the structure to create more prominent rocks, in this case leaving the most evident space between the rocks.

In this photo it is evident the different work to which we have subjected the micro-cribs of the crib with a different type of incision, up to the hills in the background very much worked and defined.

The molded rocks are used to create the walls in the foreground, they stick to themselves with plaster or cement, but only after having immersed them in water, otherwise the dry plaster of the mold does not adhere to the wall.

To mix the parts together, “dirty” plaster can be used, that is, plaster to which residues, soil and other have been added to simulate the crumbling parts of these rocks.

Processing example.

The plaster is placed on the wall randomly, when it is still soft and therefore malleable, trying with a spatula to lift it in some places to create the typical rock breaks.

It is possible to insert walls or other and work directly with the wall to amalgamate everything, obviously using the Catalan technique.

The finished and colored wall.

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roccia presepe

Here is another example of rocks.

Here the base was covered with plaster gauze, to prevent the styrofoam from escaping during the incision of the wall. The part we can make it more jagged, or mò of Norwegian fjord, and you can leave a space between the rocks.

The molded rocks are mixed with the plaster that is inserted to create additional bonding rocks, and finally to make the structure more real, before the plaster is completely dry, it is dusted with gypsum mixed with small residues of the same mixed dry. Once the coloring is complete, add soil and small natural stones.

roccia presepe

The finished and colored wall can be enriched with natural elements such as moss lichens, teloxis, dry twigs and what is available.

Another example of rock almost entirely made with cork and bark.

Avoid covering the bark too much with chalk, otherwise you risk losing the wrinkled effect of the same.

The gypsum, liquid, is sprinkled with a brush, in some cases it is not even necessary as the cork itself already has an adequate movement and coloring, see the Neapolitan crib in which the use of cork is completely different.

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colorazione spunti

Examples of backgrounds from which to take inspiration for coloring.

spunti colorazione paesaggio presepe

An example of the construction of a cave, in particular that of Lourdes

Polystyrene structure and plaster processing, for the processing of plaster we can use any technique, not only the Catalan one. To sculpt, use a punch and a chisel.

Other examples of molded rock walls and with a mixed technique to create a natural cave. These are works of the group of friends of the crib Monte Porzio catone.

Base made using wooden rods on which is placed a metallic net, that of mosquito nets so to speak, on which the barks are glued.

To help with the grouting, to cover the holes and to avoid waste of plaster, use gypsum-soaked foam rubber, this is very useful to insert into large and difficult to reach holes.

rocce presepe

Finally, here are examples taken from the web

To create the rock wall, only polystyrene is used, without the addition of plaster or other.

Chisels and awls are used as tools and pieces of the same material are added to create other rocks and movements.

For innovative ideas and techniques never before described, I recommend my VIDEOCORSO IN DVD, an unmissable opportunity not to be missed to become an expert in the field

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